18 PEOCEEDINGS OF THE NATIONAL MUSEUM vol.81 



species, though it has a somewhat different appearance. It has a 

 cucumber-shaped body, slightly curved at the middle, and beset with 

 a slightly irregular truncate tip. In these points it somewhat re- 

 sembles Semperella cucumis Schulze. There are indeed some dif- 

 ferences as above mentioned, but these may be explained as individual 

 variations. The specimen has a total length of 167 mm. The basal 

 regions are much injured and have fallen off. 



In the specimens of this species hitherto known the diactinic 

 marginalia, which project from near the peak of the sponge body, are 

 not present, while in the present specimens (except H) they always 

 show a distinct, short, brushlike appearance. These diacts are ar- 

 ranged nearly in one series, projecting from the elevated ridges near 

 the conically pointed tip of the sponge body. They measure 10 mm 

 to 20 mm in length, projecting from the surface of the ridge about 

 half or more of the entire length, and 8 mm to 12 mm in breadth at 

 the center. Frequently among these diacts, there occur spicules beset 

 with prickles, bent very slightly obliquelj^ upward and outward, and 

 disposed in two opposite rows along the distal part of the external 

 portion. This spicule slightly resembles that represented in the 

 younger specimen of the Challenger collection but it is doubtful 

 whether it represents the remains of those projecting from the top 

 of the beveled longitudinal edges or whether it belongs entirely to a 

 different category. 



In the large specimens from Station 4934 I find a larger isolated 

 form of amphidisks about 280/x long, provided with 8 to 12 paddle- 

 like and terminally slightly pointed or only rounded rays. Besides 

 these, though nearly absent or very rarely present in the smaller 

 specimens (A to E), I find a sparsely distributed, similar form of 

 medium-sized amphidisks present in the larger specimens (F to H). 

 The slender middle-sized amphidisk occurring in the Challe7iger 

 specimens may be lacking in all the specimens of this species in the 

 collection. 



Among the ectodermal pentact pinules, there occur also fairly 

 abundant pinules that have big, long, straight paratangentials, meas- 

 uring 12/i broad and lOSjn long and beset with prominent hooklike 

 lateral spines. 



The heteropole uncinate, which is nearly allied to the uncinatum- 

 like oxydiact in the Challenger specimen of this species, occurs rarely 

 in the hypoderm of specimen H. 



The anchorlike spicule of the basal tuft frequently forms a 

 strongly developed trif urcate anchor at its lower end, measuring 140jli 

 in width. This spicule in large bundles is intermixed w^ith the 

 ordinary basal spicule, which ends in an anchorlike structure, beset 

 with two long recurved opposite teeth in the same plane. The shaft 

 is biseriate with alternately disposed barbules. 



