PORIFERA. I. 



the Scaw; it is a digitate, branched species, by the structure of its skeleton and the form of its spiciales 

 closely related to the present one, with which, however, it would seem that it cannot be identified. 



Locality: Onundafjord in Iceland, depth lo fathoms, 3 specimens (the author); west of Iceland, 

 depth 22 fathoms, a little fragment (Drechsel); the bank southwest of Sudero, one specimen (Jorgensen); 

 the Faroe Islands, a little specimen (^Miiller). 



2. P. caulifera \"osm. 



PI. II, Figs. I, 2. PI. VIII, Figs. 4, 5, 6. 



1882. Pachychalina caulifcya Vosmaer, Niederl. Arch, fiir Zoologie, Supplementsband I, 1881—82, 33,15, 



Tab. I, Fig. 14, Tab. Ill, Figs. 64—66. 

 1887. Pachylhia caulifera Levinsen, Dijmphna-Togtets zool.-bot. Udbytte. 1887, 350, 8, Tab. XXIX, 

 Fig. 4, Tab. XXX, Fig. i. 



Stipitate, club- oy fingershaped^ imbranched (younger specimens) or more or less richly bratiched 

 (older specimens) ; the branches cylindrical or someivhat compressed. The Jibres form a regular ske- 

 leton of longitudinal and transverse fibres, the meshes quadratic or rectangular. The longitudinal 

 fibres zvith a few spicules., sofnetimes loith only a single series., the transverse fibres formed of single 

 spicules. Only little spongin^ forming no distinct sheath, or only a very thin one. The surface quite 

 delicately shaggy from projectitig spicules. Oscula spread ; sometimes especially found on one side of 

 the branches, sometimes they are placed in roius on the edges of the compressed branches. The spicules 

 oxea^ evenly tapering^ O'liS — 0'i4S""". 



Pachychalina caulifera was etablished in 1882 by \"osmaer on an unbranched, oarshaped 

 specimen; in 1887 Levinsen referred some unbranched, or at most twobranched cylindrical sponges 

 from the Kara Sea to this species. I have before me two specimens, both richly branched and con- 

 siderably larger than those described. The larger specimen has a height of 49''", and is richh- branched, 

 the originally few branches di\-iding into more and more; and the branches, being at the base some- 

 what compressed, are at the top cylindrical or all but cylindrical, and are here rather thin, their dia- 

 meter being between 5""" and 10""". The other specimen is shorter; is has a height of 27^"', but the 

 branches, which are also somewhat compressed, are comparatively thicker, and do not become c}lin- 

 drical at the top, where the larger diameter is 10 — 18"'". Both specimens have a distinctly marked 

 stalk being in both full 5"" long. The colour (in spirit) is light brown to light yellow. The stalk is 

 darker brown, so that we have here a colouring similar to that shown in the figure of Vosmaer (I.e.), 

 but not, however, with the sharp boundary shown in that figure. The consistency is spong\' and 

 elastic, the stalk is hard. The surface of the sponge is even and looks almost smooth, although it is 

 densely, but quite short shaggy, the spicules of the ends of the primar}- fibres projecting a little. The 

 dermal membrane appears as a thin transparent membrane; it rests on the subjacent .skeleton, and if 



of Homoeodictya are dried , as is often the case with old specimens in museums. These specimens have perhaps been 

 washed out at the preparation, or, what is also often the case, they have been found dead on the beach, and the soft parts 

 have long ago rotted and been washed away. In such cases the chete, which are not connected with the skeleton, 

 would either be quite wanting or only a few be left. It is also to be supposed that such a confounding has taken place 

 more than once. 



