456 



HexactinelUda, 



Hexasterophora. 



Farn. Rossellidae. 



Schaudinnia Schulze. 



S. rosea Frstdt. 



1887. Hyalonema rosea Fristedt, Vega-Exp. vetensk. lakttag. IV, 411, Pi. 23, 

 figs. 1 — 11, PI. 25, fig. 5. 



Of this species we have an entire specimen which is 

 elongately sack-shaped; it has a length of 90 mm and a 

 diameter of about 30 mm, the body wall is at most 5 mm 

 thick; above it is somewhat constricted towards the osculum 

 which has a diameter of scarcely 15 mm and is provided with 

 a marginal fringe. Further we have som fragments of a larger 

 specimen in which the body wall is considerably thicker, up 

 to 14 mm. The description which Fristedt gives of his 

 Hyalonema rosea shows that he has only had fragments, and 

 therefore he has got a wrong idea of the shape of the sponge. 

 The spicules in my specimens agree completely with those de- 

 scribed and figured by Fristedt. — 1 think it also beyond 

 doubt, that the species is identical with Shaudinnia arctica 

 Schulze (Faun. Arctica, I, 1900, 87, Tab. 1, Fig. 1-6, Tab. II— 

 III); the author declares (1. с 108), that besides the three species 

 of arctic Hexactinellids described in the work cited, only two 

 other arctic species are known, collected on the Albatross- 

 expedition; he thus evidently has overlooked the work of Fri- 

 stedt. — The only thing which does, that I am not quite 

 sure in my identification of the two species rosea and arctica 

 is, that I have not been able to find the discohexasters, and 

 such were not found by Fristedt too; otherwise the descrip- 

 tion by Schulze is quite agreeing, and f. inst. the pentactine 

 hypodermalia with strong spines on the tangential rays are 

 quite the same, and likewise the various forms of oxyhexasters 

 and derivate-oxvhexactines as also the autodermal diactines. 



