taxonID	type	description	language	source
AF2487CE1467FFFCFCA9E8A63299FCE3.taxon	description	(FIG. 2 A, B)	en	Goodwin, Claire E., Picton, Bernard E. (2009): Demosponges of the genus Hymedesmia (Poecilosclerida: Hymedesmidae) from Rathlin Island, Northern Ireland, with a description of six new species. Zoological Journal of the Linnean Society 156 (4): 896-912, DOI: 10.1111/j.1096-3642.2008.00498.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00498.x
AF2487CE1467FFFCFCA9E8A63299FCE3.taxon	materials_examined	Type material: Holotype: specimen in IMS, section and spicule preparation from tissue sample (Rathlin Island sponge biodiversity project; Damicornis Bay, 55 ° 17.433 ′ N, 06 ° 15.137 ′ W; water depth, 29.6 – 32.6 m; Mc 2626). Collected by J. Jones and C. Goodwin, 6 July 2005. Paratypes: Specimen 1, specimen in IMS, section and spicule preparation from tissue sample (Rathlin sponge biodiversity project; Damicornis Bay, 55 ° 17.463 ′ N, 06 ° 15.235 ′ W); water depth, 32 – 35 m; Mc 3189). Collected by J. Jones and L. Scally, 17 August 2005. Specimen 2, specimen in IMS, section and spicule preparation from tissue sample (Rathlin sponge biodiversity project; Damicornis Bay, 55 ° 17.460 ′ N, 06 ° 15.238 ′ W; water depth, 27 – 32 m; Mc 3036). Collected by J. Jones and L. Scally, 10 June 2005.	en	Goodwin, Claire E., Picton, Bernard E. (2009): Demosponges of the genus Hymedesmia (Poecilosclerida: Hymedesmidae) from Rathlin Island, Northern Ireland, with a description of six new species. Zoological Journal of the Linnean Society 156 (4): 896-912, DOI: 10.1111/j.1096-3642.2008.00498.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00498.x
AF2487CE1467FFFCFCA9E8A63299FCE3.taxon	etymology	Etymology: Named from the Latin cohereo, meaning connected, and the Latin for stick or shaft, bacillum, because of the fusion of the alae to the shaft in the chelae.	en	Goodwin, Claire E., Picton, Bernard E. (2009): Demosponges of the genus Hymedesmia (Poecilosclerida: Hymedesmidae) from Rathlin Island, Northern Ireland, with a description of six new species. Zoological Journal of the Linnean Society 156 (4): 896-912, DOI: 10.1111/j.1096-3642.2008.00498.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00498.x
AF2487CE1467FFFCFCA9E8A63299FCE3.taxon	description	External morphology: Patches formed small encrustations on boulders, and were 6 – 10 cm in maximum diameter. The external appearance is a cream to buff crust, with raised white pore sieves. One of the specimens had a large number of diatoms in its surface tissues, and small numbers of diatoms were present in the other specimens. Skeleton: Basal layer of acanthostyles with ascending columns of ectosomal spicules, of 6 – 8 spicules in width. Dense layer of chelae at the surface; chelae also present in small numbers throughout the tissue. Both specimens also had diatoms present in the surface layer, and were 400 – 600 - Mm thick. Spicules: Acanthostyles – two size categories present. Both categories are similar in form, with the head marked by large, dense spines, and a shaft entirely spined with smaller spines. 1. Large acanthostyles: 140 – 220 Mm (180 Mm) by 14 – 16 Mm (head), or by 8 – 10 Mm (shaft). 2. Small acanthostyles: 70 – 95 Mm (78 Mm) by 10 – 14 Mm (head), or by 6 – 8 Mm (shaft). 3. Ectosomal spicules: 150 – 240 Mm (202 Mm) by 3 – 4 Mm, with the majority being between 185 and 210 Mm in length; strongylote in form, and often polytylote. 4. Chelae: very abundant chelae are present [17.5 – 20 Mm, (18 Mm)]. These are rather palmate in form, the lateral alae coalesce with the shaft over their entire length, and the shaft is only slightly curved, appearing straight under the light microscope. However, the end of the median ala is not widened. There are also occasional normal arcuate chelae of the same size range.	en	Goodwin, Claire E., Picton, Bernard E. (2009): Demosponges of the genus Hymedesmia (Poecilosclerida: Hymedesmidae) from Rathlin Island, Northern Ireland, with a description of six new species. Zoological Journal of the Linnean Society 156 (4): 896-912, DOI: 10.1111/j.1096-3642.2008.00498.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00498.x
AF2487CE1467FFFCFCA9E8A63299FCE3.taxon	discussion	Remarks: Comparatively few species of Hymedesmia have chelae in which the lateral alae are fused onto the shaft. Of those that do, Hymedesmia palmatichela Topsent, 1928 has similar acanthostyles in terms of size and form, and also has polytylote ectosomal spicules, although these are larger (215 – 280 Mm), and its chelae are of a much larger size (45 – 46 Mm). Hymedesmia cordichela Alander, 1942 has spicules of the same size, but the chelae have distinctive ‘ cordate leaves’, and the ectosomal spicules are not polytylote. In Hymedesmia palmatichelifera Van Soest, 1984, the primary acanthostyles are larger (293 – 361 Mm), the ectosomal spicules are tornotes rather than strongyles, and the large acanthostyles are smooth at their tips. Hymedesmia jamaicensis Van Soest, 1984 possesses ‘ whispy’ tornotes rather than strongylote ectosomal spicules.	en	Goodwin, Claire E., Picton, Bernard E. (2009): Demosponges of the genus Hymedesmia (Poecilosclerida: Hymedesmidae) from Rathlin Island, Northern Ireland, with a description of six new species. Zoological Journal of the Linnean Society 156 (4): 896-912, DOI: 10.1111/j.1096-3642.2008.00498.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00498.x
AF2487CE1461FFFDFF0FEDEB32BCFA5D.taxon	materials_examined	Type material: Holotype: specimen in IMS, section and spicule preparation from tissue sample (Rathlin Island sponge biodiversity project; Loch Garry, 55 ° 15.956 ′ N, 06 ° 10.411 ′ W; water depth, 32 – 35 m; Mc 2645). Collected by J. Jones and L. Scally, 9 June 2005. Etymology: Named from the Latin for umbrella, umbella, in reference to the rays of spongin on the surface, which look rather like umbrella spokes. Comparative material examined: Hymedesmia mammilaris Fristedt, 1885, spicule preparation prepared by Alander (1942), from material from Skagerack station 13, 9 July 1934, and from Skagerack, 5 August 1937 (subspecies).	en	Goodwin, Claire E., Picton, Bernard E. (2009): Demosponges of the genus Hymedesmia (Poecilosclerida: Hymedesmidae) from Rathlin Island, Northern Ireland, with a description of six new species. Zoological Journal of the Linnean Society 156 (4): 896-912, DOI: 10.1111/j.1096-3642.2008.00498.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00498.x
AF2487CE1461FFFDFF0FEDEB32BCFA5D.taxon	description	Skeleton: Basal layer of acanthostyles, evenly dispersed, in which the small acanthostyles are much more abundant than the large ones. Because of the thickness of the sponge, even the largest acanthostyles do not reach the sponge surface. It has ascending columns of ectosomal spicules, of 10 – 15 spicules in width. Chelae are present throughout the tissue, but are most abundant at the surface, where they form a dense layer. The sponge is 900 – 1200 - Mm thick. Spicules: 1. Large acanthostyles: 300 – 525 Mm (434 Mm) by 12 – 14 Mm at the head, or by 10 Mm on shaft. Long slender acanthostyles that have a well-developed tylote head. The majority are spined only on the head, but in some the shaft is spined with very small spines, which give a roughened texture, for up to half of their length. The spines on the head are rather short, and may have rounded points. 2. Small acanthostyles: 130 – 210 Mm (167 Mm) by 12 Mm (head), or by 6 – 10 Mm (shaft). Entirely spined with medium-sized spines. The head is slightly tylote, and is marked by more numerous spines. There is often a small unspined gap on the shaft, just above the head. 3. Ectosomal spicules: 270 – 380 Mm (336 Mm) by 6 – 10 Mm. Long tornotes that are style-like in form. The majority are formed into a fine point at one end, with the other end either abruptly pointed or rounded. They are slightly fusiform, and tend to taper towards the more sharply pointed end. 4. Chelae: 20 – 25 Mm (23 Mm), with a broad shaft; abundant. Remarks: The size of the spicules roughly equate with those of H. mammilaris, which has large acanthostyles (300 – 400 Mm), small acanthostyles (120 – 200 Mm), oxeote ectosomal spicules (up to 360 Mm), and chelae (19 – 25 Mm). However, the large acanthostyles of H. mammilaris are shorter, and are spined for at least half of their length, and both the large and small acanthostyles lack a tylote head. Additionally, this species is red when living. Hymedesmia simillima is also similar. However, its acanthostyles are longer (410 – 650 Mm), the small acanthostyles have more spines, and the ectosomal spicules are true oxeas, tapering to a fine point, rather than being like styles, as in H. umbelliformis sp. nov. The chelae are more strongly curved, and are larger in size (28 – 37 Mm). Hymedesmia proxima can be distinguished from H. umbelliformis sp. nov. by its fusiform ectosomal spicules, and by the differences in spination on its acanthostyles: both categories are more spined than H. umbelliformis sp. nov., and the spination on the large acanthostyle extends further up the shaft. The larger acanthostyles also reach a greater length (620 Mm). Hymedesmia basispinosa can also be differentiated, as its ectosomal spicules are clearly oxea, and are often mucronate at the ends, and are longer, reaching up to 500 Mm in length.	en	Goodwin, Claire E., Picton, Bernard E. (2009): Demosponges of the genus Hymedesmia (Poecilosclerida: Hymedesmidae) from Rathlin Island, Northern Ireland, with a description of six new species. Zoological Journal of the Linnean Society 156 (4): 896-912, DOI: 10.1111/j.1096-3642.2008.00498.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00498.x
AF2487CE1460FFFEFF6CE8743741FDE9.taxon	description	(FIG. 4 A, B) Type material: Holotype: specimen in IMS, section and spicule preparation from tissue sample (Rathlin Island sponge biodiversity project; Duncan’s Bo, 55 ° 18.718 ′ N, 06 ° 15.123 ′ W; water depth, 29 – 32 m; Mc 2897). Collected by B. Picton and C. Goodwin, 6 September 2005. Etymology: Named from the Latin Crater, meaning a bowl, or the crater of a volcano, as the raised rims of the pore sieves give a crater-like appearance. Comparative material examined: Hymedesmia proxima Lundbeck, 1910, spicule preparation of specimen from Ingolf expedition station 85. ZMUC.	en	Goodwin, Claire E., Picton, Bernard E. (2009): Demosponges of the genus Hymedesmia (Poecilosclerida: Hymedesmidae) from Rathlin Island, Northern Ireland, with a description of six new species. Zoological Journal of the Linnean Society 156 (4): 896-912, DOI: 10.1111/j.1096-3642.2008.00498.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00498.x
AF2487CE1460FFFEFF6CE8743741FDE9.taxon	description	Skeleton: Basal layer of acanthostyles, evenly dispersed, in which the small acanthostyles are more abundant than the larger category. It has ascending columns of ectosomal spicules, 10 – 15 - spicules thick, and the orientation of the ectosomal spicules in these columns is not uniform: some point up and others point down. There is a dense layer of chelae at the surface, and chelae are also present in small numbers throughout the sponge tissue. The sponge is 700 – 800 - Mm thick. Spicules: 1. Large acanthostyles: 335 – 620 Mm (452 Mm) by 12 – 20 Mm on the head, or by 8 – 14 Mm on the shaft. The majority are between 400 and 500 Mm in length. These have a very slightly tylote head, and are spined for about two-thirds of their length with very small spines (much smaller than those on the small acanthostyles). On some, the spines are barely perceptible, giving a roughened appearance. The spines on the head are slightly larger than those on the shaft, and often have rounded tips. The spicules are often curved. 2. Small acanthostyles: 130 – 220 Mm (164 Mm) by 14 – 16 Mm at the head, or by 8 – 10 Mm on the shaft. The majority are between 140 and 190 Mm long. These are entirely spined, with a slightly tylote head. The shaft is densely set with small recurved spines, on the head, these are slightly bigger, and even more numerous. The spicules are often curved. 3. Ectosomal spicules: 260 – 350 Mm (312 Mm) by 6 – 10 Mm. Most of the spicules are styles, in which one end of the spicule is rounded and the other end tapers to a sharp point. However, a few are more tornote-like in form, with the blunter end very slightly pointed, and the other end coming to a more abrupt point. They are very variable in width, and the fatter ones are sometimes fusiform, and occasionally faintly polytylote. 4. Chelae: arcuate chelae are present, and are of 20 – 27.5 Mm (23 Mm) in length. Remarks: H. proxima has spicules that are similar in size to this species. However, the ectosomal spicules of H. proxima are fatter, 8 – 12 Mm in width, and are uniformly fusiform, rather than variable in form. The small acanthostyles do not have a developed head, or any difference between the spination of the head and the shaft, and the large acanthostyles do not have a tylote head. The chelae are also less robust. Lundbeck also reports that this species is hispid. Hymedesmia irregularis has acanthostyles that are more similar in form, with tylote heads; however, these are not divisible into two size categories. Additionally, its ectosomal spicules are always polytylote, and the chelae are much larger (40 – 50 Mm).	en	Goodwin, Claire E., Picton, Bernard E. (2009): Demosponges of the genus Hymedesmia (Poecilosclerida: Hymedesmidae) from Rathlin Island, Northern Ireland, with a description of six new species. Zoological Journal of the Linnean Society 156 (4): 896-912, DOI: 10.1111/j.1096-3642.2008.00498.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00498.x
AF2487CE1463FFF0FCB4ECFB31DFFD27.taxon	materials_examined	Type material: Holotype: specimen in IMS, section and spicule preparation from tissue sample (Rathlin Island sponge biodiversity project; Damicornis Bay, 55 ° 17.459 ′ N, 06 ° 15.233 ′ W; water depth, 32 – 35 m; Mc 2792). Collected by C. Goodwin and D. Goodwin, 15 August 2005. Paratypes: 11 further specimens (specimen in IMS, section and spicule preparation from tissue sample), all from the Rathlin sponge biodiversity project (Mc 2399, 2472, 2644, 2692, 2722, 2743, 2810, 2859, 3115, 3147, and 3150). Comparative material examined: Hymedesmia versicolor Topsent, 1893. DT- 86: thick section derived from the holotype. Monaco, 1928, no 42. MNHN. DT- 87: thick section derived from paratype. Station 299, 1908, no. xI 172.19. MNHN. DT- 198: specimen in alcohol. Banyuls. MNHN. Etymology: Named for Rathlin Island, the type locality. External morphology: A distinctive sponge, which may be recognised in situ. Forms small patches of 3 – 5 cm in diameter, often with several patches adjacent to one another; each patch bears one or two oscules. The oscules are combined with inhalent pore sieves at the tip of inflated papillae, which project from the sediment that the sponge is frequently covered in. The colour of the sponge is bright yellow, sometimes with darker yellow or orange lines radiating from the papillae. It turns a dark brown / black in alcohol. Skeleton: Basal layer of acanthostyles, in which the small acanthostyles are very abundant. The larger acanthostyles tend to be surrounded by the columns of ectosomal spicules. It has ascending columns of ectosomal spicules that are variable in thickness: between 5 and 12 spicules in width. Chelae are present in the surface layer, but are not very abundant. The sponge is ~ 900 - Mm thick. Spicules: 1. Large acanthostyles: 175 – 390 Mm (282 Mm) by 10 – 14 Mm. Spined for between half and two-thirds of their length, with small straight spines. The head is not tylote. 2. Small acanthostyles: 65 – 125 Mm (103 Mm) by 10 – 12 Mm. Spined for their whole length, again the head is not tylote. The spines are very large, and are usually straight (although some are very slightly curved). 3. Ectosomal spicules: tylotes 220 – 335 Mm (280 Mm) by 4 – 6 Mm, most with both ends tylote, but in some, only one end is swollen. 4. Chelae: arcuate chelae 22.5 – 27.5 Mm (25 Mm) along shaft, with fairly short alae. Remarks: The spicules are similar in size to H. versicolor. Hymedesmia versicolor has strongly curved large acanthostyles that have a slightly tylote head, and a largely smooth tip, and are 340 – 450 Mm by 8 – 11 Mm (at the head), small acanthostyles that are 115 – 180 Mm by 7 – 10 Mm (at the head), ectosomal spicules that are 250 – 325 Mm by 2 – 5 Mm, and chelae that are 25 – 30 - Mm long. However, we have examined sections from the type of this species, and a paratype and the skeletal structure precludes its inclusion in the genus Hymedesmia. It has a reticulate choanosomal skeleton formed of bundles of large acanthostyles, which are echinated with smaller ones. There is also a dense layer of strongyles at the surface (Fig. 6). These characters would indicate inclusion in Lissodendoryx (Ectyodoryx) Lundbeck 1909. The skeleton is not described in the original description (Topsent, 1893), or the redescription (Topsent, 1936). However, Topsent originally placed the species in the genus Myxilla. Further examination of the numerous paratypes is necessary to fully resolve the taxonomy of this species. Topsent (1893, 1936) notes that the colour and the presence of microscleres in this species is variable, and it is possible that it encompasses more than one species, some of which may be Hymedesmia. Other authors have ascribed specimens to H. versicolor, including Sara (1961), Cabioch (1968), and Boury-Esnault (1971), and there may be a Hymedesmia with similar spiculation that remains undescribed. Unfortunately, none of these authors describe the skeleton of their specimens in detail. Hymedesmia rathlinia sp. nov. differs in spiculation to H. versicolor, in that the spines in the latter are very small, giving the acanthostyles a roughened appearance, whereas the spines in H. rathlinia sp. nov. are pronounced, particularly on the small acanthostyles. Both categories of acanthostyles of H. versicolor are larger than those found in H. rathlinia sp. nov. The ectosomal tylotes of H. versicolor are asymmetrical, with one end tylote and the other tapering to a rounded point, whereas both ends in H. rathlinia sp. nov. are normally symmetrical, with both ends being tylote. Since the Rathlin survey H. rathlinia sp. nov. has also been found to be present on the Maidens, a group of rocks on the east coast of Northern Ireland.	en	Goodwin, Claire E., Picton, Bernard E. (2009): Demosponges of the genus Hymedesmia (Poecilosclerida: Hymedesmidae) from Rathlin Island, Northern Ireland, with a description of six new species. Zoological Journal of the Linnean Society 156 (4): 896-912, DOI: 10.1111/j.1096-3642.2008.00498.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00498.x
AF2487CE146DFFF1FF79ECA733CFFC5C.taxon	materials_examined	Comparative material examined: Hymedesmia peachii type specimen, 1877.5.21.1137 (Bk). BMNH. External morphology: A very thin pale peach to yellow encrustation, with oscules surrounded by radiating veins. Two specimens were taken: one from Ruecallan on the North Wall, and one from the White Cliffs on the south of the island (29 – 33 m). Both formed fairly large patches (with a maximum diameter of <15 cm) on rock. Skeleton: Basal layer of acanthostyles, with ascending columns of ectosomal spicules, 3 – 8 spicules thick. Chelae are present in the surface layer. It is a thin sponge that is 500 – 600 - Mm thick. Spicules: 1. Acanthostyles: 75 – 320 Mm by 8 – 14 Mm; only one size category is present. The smallest acanthostyles are entirely spined, whereas those at the larger end of the size range may be smooth for up to half of their length. The head is not tylote, and the spicules are sometimes faintly or strongly curved. Extremes of this category are shown in Figure 7 a; however, there are intermediates in both size and form. 2. Ectosomal spicules: 165 – 225 Mm by 4 – 5 Mm; tornotes with conical ends. 3. Chelae: two size categories of chelae are present. The largest chelae (28 – 30 Mm) have an unusual, broad, flattened shaft, whereas the smaller chelae (20 – 22 Mm) are normal arcuate chelae. Remarks: The spicules differ slightly from the sizes reported by Bowerbank (acanthostyles up to 379 Mm in length, ectosomal spicules 144 - Mm long, chelae 42 - and 13 - Mm long, respectively), but are the same in form. The sizes agree more closely with those described by Burton (1930), although he stated that the acanthostyles fall into two size classes, and that only large chelae are present.	en	Goodwin, Claire E., Picton, Bernard E. (2009): Demosponges of the genus Hymedesmia (Poecilosclerida: Hymedesmidae) from Rathlin Island, Northern Ireland, with a description of six new species. Zoological Journal of the Linnean Society 156 (4): 896-912, DOI: 10.1111/j.1096-3642.2008.00498.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00498.x
AF2487CE146CFFF2FF05EA60364CFDD9.taxon	materials_examined	Type material: Holotype: specimen in IMS, section and spicule preparation from tissue sample (Rathlin Island Sponge Biodiversity Project; Damicornis Bay, 55 ° 17.436 ′ N, 006 ° 15.003 ′ W; water depth, 30 – 35 m; Mc 2606). Collected by B. Picton and A. Mahon, 6 July 2005. Paratypes: specimen 1, specimen in IMS, section and spicule preparation from tissue sample (Rathlin Island Sponge Biodiversity Project; Damicornis Bay, 55 ° 17.459 ′ N, 006 ° 15.233 ′ W; water depth, 27 – 32 m; Mc 2790). Collected by C. Goodwin and D. Goodwin, 15 August 2005. Specimens 2 and 3: specimens in ethanol, sections and spicule preparations from tissue sample (Sublittoral Survey Northern Ireland Project; Russells Rock, The Maidens, 54 ° 57.291 ′ N, 005 ° 45.008 ′ W; water depth, 25 – 30 m; Mc 3955 and Mc 3960). Collected by C. Goodwin and D. Goodwin, 24 August 2007. Specimen 4: specimen in IMS, section and spicule preparation from tissue sample (south-west of Lunga, Firth of Lorne, western Scotland; 56 ° 12.53 ′ N, 005 ° 43.40 ′ W; Mc 492). Collected by B. Picton, 31 December 1981. Etymology: Named from the Latin stella, meaning star, and fero, meaning to bear, because of the starshaped pattern on its surface. External morphology: Bright yellow / orange sponge forming large patches (over 20 cm in diameter), which are very conspicuous because of their bright colour and oscule form. Prominent oscules surrounded by numerous (10 – 20) oscular channels, some of which are branched. The oscules are regularly spread over the sponge surface, and are arranged in diamonds. The ends of the oscular channels touch those of neighbouring oscules, giving the surface a regular star-type pattern. Skeleton: Basal layer of large and small acanthostyles, from which ectosomal spicules arise in columns that are 10 – 15 spicules thick. The smaller acanthostyles are more abundant. Sigmas are very abundant throughout the tissue. Chelae are present in certain regions of the sponge, but may not be apparent in some specimens. Where present, they are reasonably common and form a layer at the suface. The sponge is ~ 800 - Mm thick. Spicules: 1. Large acanthostyles: 265 – 440 Mm (358 Mm) by 8 – 12 Mm. These are fusiform acanthostyles with a tylote head. The shaft is smooth, and the head is sparsely spined with small, rounded spines. Occasional spicules are present, consisting of two of these acanthostyles fused at the head. 2. Small acanthostyles: 65 – 95 Mm (79 Mm) by 8 – 10 Mm. These acanthostyles are very characteristic in appearance; they taper evenly to a sharp point, with no development of the head. The majority of the shaft is spined with large spines, but the last eighth to one-quarter, towards the tip, is smooth, and there are smooth areas on the shaft above the head. 3. Ectosomal spicules: the styles are 210 – 290 Mm (247 Mm) in length, with the majority of being 8 – 10 - Mm wide, but with some much thinner spicules of 3 – 5 Mm in width. These spicules are fusiform: one end is rounded and tylote, and the other end is pointed; some are mucronate at the tip. 3. Sigmata: 10 – 12 Mm in length. 4. Chelae: 15 – 18 Mm in length. These are small chelae, with leaf-like alae, and are only joined to the shaft by a short section at the top. The alae have a claw-like appearance when viewed under the light microscope. Remarks: Based on its skeletal structure, this species is in the genus Hymedesmia. The smooth, large acanthostyles are unusual for this genus, and are very similar in form to Lissodendoryx (Ectyodoryx) atlanticus. However, in the subgenus Ectyodoryx, the choanosomal skeleton is composed of either styles or acanthostyles, with a separate category of ectosomal tornotes. The pronounced difference in the form of the acanthostyles is also unusual. The smaller acanthostyles are very similar in form to those of Hymedesmia zetlandica Bowerbank, 1864, which is the type specimen of the genus Hymedesmia. Chelae were not visible in tissue sections from either the Rathlin specimens or the Lunga specimen, despite numerous sections being taken from different tissue areas, although scarce chelae were visible in the spicule preparations. However, chelae were numerous in some areas of the surface of two specimens collected from the Maidens: this suggests that chelae are present only in certain regions of the sponge. It was not possible to determine which precise regions they were associated with. Embryos were present in the Lunga specimen. These embryos have different spicules to the main tissue: thin, short styles (125 Mm by 2 Mm), and unguiferous anchorate chelae (20 Mm). The majority of the chelae have three claw-shaped alae on each end, but in some individuals there were up to five. In several cases, spines are present on the chelae shaft just below the alae. SUBGENUS STYLOPUS FRISTEDT, 1885	en	Goodwin, Claire E., Picton, Bernard E. (2009): Demosponges of the genus Hymedesmia (Poecilosclerida: Hymedesmidae) from Rathlin Island, Northern Ireland, with a description of six new species. Zoological Journal of the Linnean Society 156 (4): 896-912, DOI: 10.1111/j.1096-3642.2008.00498.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00498.x
AF2487CE146FFFF3FCBBECE23087FD49.taxon	description	(FIG. 9 A, B) Type material: Holotype: specimen in IMS, section and spicule preparation from tissue sample (Rathlin Island Sponge Biodiversity Project; White Cliffs, 55 ° 17.542 ′ N, 06 ° 14.507 ′ W; water depth, 30 – 33 m; Mc 2653). Collected by B. Picton and A. M. Mahon, 7 July 2005. Etymology: Named for the cream colour of the surface, from the Latin crami for cream. Comparative material examined: Hymedemsia dermata Lundbeck, 1910, spicule preparation of specimen from Forsblads Fjord in East Greenland (Amdrup expedition 1900). ZMUC. External appearance: Thin, cream incrustation on boulder, with a maximum diameter of 5 cm. There are no obvious pore sieves, and the surface appears slightly hispid and is covered in a thin layer of silt. Skeleton: Basal layer of acanthostyles, sparsely distributed, with a roughly even ratio of large to small acanthostyles. There are ascending columns of ectosomal spicules that are 10 – 15 spicules thick, which fan out towards the surface, and may adjoin with adjacent columns. The sponge is 900 – 1000 - Mm thick. Spicules: 1. Large acanthostyles: 370 – 550 Mm (436 Mm) by 12 – 18 Mm. Head, very slightly tylote; shaft, mainly smooth, with the bottom eighth to one-quarter covered in very small spines, giving it a roughened appearance. The spines on the head may be rounded at the tip. 2. Small acanthostyles: 105 – 175 Mm (136 Mm) by 12 – 14 Mm; the head is not tylote, and is entirely spined with recurved spines, the size of which vary between individual spicules (small – large). In some individuals the spines on the head are larger, and may have rounded tips. 3. Ectosomal spicules: 290 – 400 Mm (360 Mm) by 4 – 7 Mm. These are strongyles in which usually one or both ends are tylote. 4. Microscleres: absent. One arcuate chela was present in the spicule preparation, but is assumed to be contamination, as chelae are not present in the tissue section. Remarks: Hymedemsia dermata has similar spicule sizes. However, it is described as having concical papillae on the surface, and the large acanthostyles are strongly spined, as opposed to the roughened texture of the acanthostyles described above. The strongyles are also thicker (6 – 10 Mm), and may be polytylote.	en	Goodwin, Claire E., Picton, Bernard E. (2009): Demosponges of the genus Hymedesmia (Poecilosclerida: Hymedesmidae) from Rathlin Island, Northern Ireland, with a description of six new species. Zoological Journal of the Linnean Society 156 (4): 896-912, DOI: 10.1111/j.1096-3642.2008.00498.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00498.x
AF2487CE146EFFF4FC8BED7130EDF9C5.taxon	materials_examined	Comparative material examined: Hymedesmia hibernica Stephens, 1916 type (W 141 14.1916). NMI. External morphology: A yellow sponge with large pore sieves, which is slightly translucent in appearance. Both specimens formed thin encrustations on rock: these are very small patches of less than 5 cm in maximum diameter. Skeleton: Basal layer of acanthostyles, in which the smaller category are more abundant, and in which acanthostyles are spread evenly but fairly sparsely, with some space in between them. The ascending columns of anisostrongyles are 5 – 8 spicules thick. The sponge is 500 – 800 - Mm thick. Spicules: 1. Large acanthostyles: 250 – 325 Mm by 5 – 12 Mm. These acanthostyles have a slightly tylote head, which is more obvious in thinner specimens, and are spined on the head and up to half of the way up the shaft, although with much smaller spines. The head spines are often strongly curved up towards the shaft. 2. Small acanthostyles: 110 – 130 Mm by 10 – 12 Mm. These are entirely spined with large recurved spines on the shaft, which become progressively sparser towards the tip; the head is not tylote, but is marked by denser spines that are often curved up towards the shaft. 3. Ectosomal spicules: 200 – 250 Mm by 2 – 4 Mm, with thin anisostrongyles. One end is usually thicker than the other, and neither end is tylote. 4. Microscleres: none present. Remarks: The spiculation agrees almost exactly with that described by Stephens (1916), apart from the tendency for the tylostyles to become subtylote. This species was originally described from 74 m off Reenacry Head, County Kerry, Ireland. It has since been recorded from the English Channel, from Roscoff (Cabioch, 1968).	en	Goodwin, Claire E., Picton, Bernard E. (2009): Demosponges of the genus Hymedesmia (Poecilosclerida: Hymedesmidae) from Rathlin Island, Northern Ireland, with a description of six new species. Zoological Journal of the Linnean Society 156 (4): 896-912, DOI: 10.1111/j.1096-3642.2008.00498.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00498.x
AF2487CE1469FFF5FC9FE8EA3697FEF5.taxon	materials_examined	Comparative material examined: Hymedemsia primitiva spicule preparation of specimens from Ingolf expedition stations 6 and 89. ZMUC. External morphology: The sponge is a thin cream crust with large pore sieves; in two of the sponges the area around the pore sieves was yellow from algae in the surface tissues. The sponge formed patches with maximum diameters in the range 4 – 15 cm. Skeleton: Basal layer of acanthostyles, in which the smaller acanthostyles are more abundant. There are ascending columns of ectosomal spicules that are 5 – 8 spicules thick. The sponge is 400 – 500 - Mm thick. Several of the specimens had diatoms present in their surface layer. Spicules: 1. Acanthostyles: 100 – 315 Mm by 10 – 16 Mm on the head, or by 6 – 10 Mm on the shaft; entirely spined with small, short, recurved spines. The head is slightly tylote, and bears slightly larger spines that often have rounded tips. In the longer spicules the spines may be very sparse towards the tip, and part of the shaft may be smooth. 2. Ectosomal spicules: 200 – 250 Mm by 2 – 4 Mm. With tylotes that are usually faintly polytylote. 3. Microscleres: absent. Remarks: The spiculation broadly agrees with that of Lundbeck’s (1910) specimens. However, the strongyles of his specimens have a slightly broader size range (196 – 280 Mm), and the acanthostyles are also somewhat thicker than the Rathlin specimens, with base widths varying from 14 to 27 Mm. However, Lundbeck states that there is much variation of acanthostyles between individuals in terms of robustness and spination. This species was originally described from deep water (108 – 840 m) around Iceland and the Faroe Islands. It has subsequently been reported from the Caribbean (De Laubenfels, 1936) and from Wembury Bay in Devon (Burton, 1957), although it would seem unlikely that the former record is of the same species.	en	Goodwin, Claire E., Picton, Bernard E. (2009): Demosponges of the genus Hymedesmia (Poecilosclerida: Hymedesmidae) from Rathlin Island, Northern Ireland, with a description of six new species. Zoological Journal of the Linnean Society 156 (4): 896-912, DOI: 10.1111/j.1096-3642.2008.00498.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00498.x
