PORIFERA. III. 



109 



in a good state, and they have especially the dermal membrane undamaged, and further it must be 

 noted, that the chelse in stylata are numerous and form a layer in the dermal membrane. Should the 

 two species be considered as identical, it must be from the point of view, that the specimens of 

 dermata were abnormal, but there is otherwise nothing to indicate such a state. Now one fact is 

 very interesting, and it is that H. stylata is from the cold area (station 113, bottom temperature 

 -r- i o C.), while the present species is from bottom with positive temperature. It is not for the first 

 time that very nearly related, but distinct species are found one on negative the other on positive 

 bottom (e.g. Gelliodes plexa and consimilis, The Danish Ingolf Exp. VI, i; Asbestopluma pennatula and 

 bihamatifera, Cladorhiza abyssicola and gelida, Lissodendoryx complicata and vicina; ibid. VI, 2.). 



Locality: Station 2, 63 04' Lat. N. , 9 22' Long. W., depth 262 fathoms; Forsblads Fjord in 

 East Greenland, depth 5090 fathoms (The Amdrup Expedition 1900). The localities lie at East 

 Greenland and West of the Faroe Islands. 



50. H. tornotata n. sp. 

 PI. Ill, Fig. 18, PI. XI, Fig. 2. 



Incrusting; surface hispid. Spicula: megasclera; the skeletal spicules acanthostyli with a more 

 or less pronounced head, entirely spined but in the longer the spines very small outwards, o-ioj o-j/""", 

 not distinctly divided into two groups; the dermal spicules long tornota, generally with microspined 

 end-parts, o-j2 0-47""". No microsclera. 



This species is represented by four specimens, three growing on shell-fragments, the fourth on 

 a Brachiopod; the former are rather small crusts while the latter covers the greatest part of the 

 Brachiopod shell and has thus an extent of 20 mm . The small specimens are about 07 mm thick while 

 the larger one reaches to a thickness of about i mm ; this comparatively great thickness is reached on 

 account of a special development of the dermal skeleton as mentioned below. The colour (in spirit) 

 is light brown to brown. The surface is densely hispid from projecting dermal spicules; the small 

 specimens are much more hispid than the large. The dermal membrane is inconspicuous and not 

 separable. Oscula and pores were not observed. 



The skeleton. The dermal skeleton consists of large bundles of dermal spicules which stretch 

 from the main skeleton to the surface, the spicules in the bundles are penicillately spread outwards 

 and project beyond the surface for a rather long distance; seen from above the projecting spicules 

 are almost stellately arranged. Such is the construction of the dermal skeleton in the small specimens, 

 but in the large specimen the facts are somewhat otherwise; the dermal spicules are here more numerous 

 and they are somewhat strongly interwoven, forming a dense and thick layer, and apparently lying 

 without any order; only outermost they are arranged somewhat parallel, with the points projecting 

 outwards; this layer may reach to a thickness of o - 8 mm . The difference in the development of the 

 dermal skeleton in this species is, as will be seen, about the same as may also occur in H. Dujardinii. 

 The main skeleton is of typical construction, consisting of vertical acanthostyli with the heads on the 

 substratum; they are placed rather densely. At the base there is an amount of spongin. 



