84 



arising from the convex side of the crossing-point of the four long, lateral rays 

 (pi. XXIII, f. 7). Young autodermalia are quite smooth and more slender than 

 adult ones. ' 



The autogastralia are represented by stout, sword-shaped oxyhexactines 

 regularly arranged in a quadratic reticulation and uniformly distributed over the 

 walls of the excurrent cavities. Their four tangential rays are gradually attenu- 

 ated to the pointed end, slightly rough and about 100 f* long. The distal, 

 radial ray imbedded in the parenchyme is similar to the tangential rays, the 

 proximal ray, which protrudes freely into the gastral cavity, is also pointed, but 

 rougher (pi. XXIII, f. 8). 



In consequence of the great similarity of nearly all the different kinds of 

 spicules with those of Lophocahjx iMlippensis F. B. Sch. there can, I think, be 

 no doubt that the sponge here described, must in spite of the difference of its 

 shape, and the fact that the radial rays of some of the autodermalia freely protrude 

 from the outer surface, be placed in the RosseUid genus Lophocalyx. That this 

 sponge seems to approach the family Asconematidx by the presence above men- 

 tioned, of protruding autodermalia, cannot induce us to remove it from the 

 Bossellidse because many observations have shown that the boundary between the 

 Asconematidce and BossellidiB is by no means a very distinct one. 



The only specimen of Lophocahjx spinosa was found to the west of the And- 

 amans in a depth of 436-531 m =238-290 fths. 



I will finally mention two specimens of Lyssacine Hexactinellids, collected by 

 the " Investigator " in the central part of the Bay of Bengal, which are so frag- 

 mentary that they cannot be determined with any degree of certainty. It there- 

 fore does not appear advisable to give them specific names and assign to them 

 definite positions in the classificatory system. 



One of the specimens is a strongly compressed fragment of the size of a 

 thumb, the original shape of which cannot be made out. 



At one point a bundle of 20-30 stout, cylindrical spicules, 300-800 /^ thick 

 protrudes. These spicules are all broken off a few centimeters from the surface. 

 They on the whole make the impression of basal root-tuft-spicules, are either 

 quite smooth or have a peculiarly granular or tuberculous surface, but nowhere 

 an indication of the presence of recurved spines or thorns (pi. IX, f. 11). 



The whole specimen seems to consist of a compressed mass of irregular spi- 

 cular fibres. It contains numerous slender oxyhexactines of various size, which 

 are doutless proper to the sponge. Other kinds of spicules, however, which are 

 present in some parts, but totally absent in others, cannot, with any degree of 

 certainty, be considered as belongiiig to it. For this reason it is impossible 

 reliably to determine the species to which the specimen belongs ; and it would be 



