20 



PORIFERA. I. 



figures, PI. \', fig. 9, are altogether mon.stroiis forni.s, while he gives no figures of the normal needles 

 of the species. 



The examination of the spicules in the Aiiiorphiiia nodosa of Fristedt, of which I have had 

 a little piece, has shown this species to be identical with H. geiiitvix. Its outer form, as described bv 

 Fristedt, 1. c, agrees also ver\' well with this \iew. In the .spiculation onl\- the smaller spicules 

 seem generally to be a little finer than in the specimen of Schmidt, and of monstrous forms I have 

 onlv seen a few. Othervise the figure by Fristedt, especially of the smaller spicule, is not correct. 

 It is easil\- understood that Fristedt has not been able to determine the species according to the 

 description and figure by Schmidt, especially, because Schmidt, as before mentioned, only gives 

 figures of monstrous needles. In Fristedt we get the information that the species can reach the 

 size of a human head. 



Locality. We have of this species four specimens and some fragments, all from West-Greenland; 

 only for one specimen a more particular localit}-, Umanak, is given. 



Geogr. distr. West-Greenland and Spitzbergen (Fristedt). 



3. H. fibrosa Frstdt. 

 PI. IX, Figs. 3 a, b, c. 

 1887. Amorphina fibrosa Fristedt, Vega E.xp. vetensk. lakttag. IV 426, PI. 24, figs. 11 — 12. 



Irregular., more or less roimdisli or i/icriistnig masses. The dermal membrane in some places 

 with a close reticulatioii op spicules^ in other places the spicules closely packed. Osciila /ezi\ spread. 

 The skeleton, consists of loose fibres, not distinctly marked. The spicules oxea., Jailing as to size in 

 tiL'o groups ; the larger o-jj — o-jp""'\ the smaller o-iy — o-2p""". 



Of this species there are in the collection some more or less roundish pieces, all fragments, and 

 some irregular crusts growing on calcareous algte. The best conserved specimens are of a rather firm 

 consistency. The skin shows in most places a reticulation of spicules, closer, but looking coarser than 

 in H. panicea; in other places the spicules are closeh' packed without forming any reticulation. Oscula 

 are few and spread. The pores are found in the meshes of the dermal reticulation as in H. panicea. 



The skeleton, consists of loose and irregular, not sharph' marked fibres, which form, at all events 

 frequently, a very irregular and indistinct network. The skin is not, or is only in the places where a 

 dermal reticulation is found, separable from the body itself as a dermal membrane properly so called; 

 in the other places the outermost layer of the sponge is remarkable by the closely packed spicules; 

 in a section perpendicular on the surface, this part appears distinctly marked off from the tissue below, 

 and this la\-er, which is developed into a skin, has a thickness of ca. o^'"™. 



Spicula are oxea, falling into two rather well defined groups of size, which are also of different 

 occurrence in the sponge. The larger ones have a length of 0-35 — o-59""", most frequently they are 

 0-47""" long; they are .slightly bent, almost of the same thickness throughout their length, and are 

 evenly, but shortly pointed; their thickness is ver\- varying, but ma\- be rather great, up to o-oi7'"'"; 

 a .swelling is not unfrequently found in the middle or nearer to one of the end.s. The smaller spicules 

 are finer, more or less curved, and vary in length between 0-17 and 0-29""". The larger spicules form 

 the .skeleton and the dermal reticulation, while the smaller ones are found in the outermost part of 



