TWO NEW SPONGILLJ] FROM LAKE TANGANYIKA. 483 



(a) The Gem mule. — The gemmuleof Spongilla tangan- 

 y ikse lacks the amphidiscs which surround the gemmule of the 

 Meyeninae. It therefore appears that this species cannot belong 

 to that sub-family. But it equally lacks the small spicules 

 which are usually found in close relation with the gemmule of 

 the Spongillinae. Potts, however, places Spongillaaspinosa 

 among the Spongillinse, in spite of the fact that its gemmules 

 lack characteristic spicules. If this arrangement be followed, 

 the absence of such spicules from Spongilla moorei and 

 Spongilla t an ganyikse should not be considered as a barrier 

 against including these species among the Spongillinse. But the 

 inclusion does away with the importance of the presence of 

 special gemmule spicules as a sub- family character. 



The thin coat of the gemmule resembles that found in 

 Spongilla moorei, Spongilla aspinosa, and others of the 

 Spongillinse, and has no similarity to the thick coat of the 

 gemmule of the Meyeninse. The characters of the gemmule, 

 therefore, as far as they go, point to this new African species 

 discovered by Mr. Moore being one of the SpongilliuEe. 



(b) The Spicules.— It is generally stated that the skeletal 

 spicules of the several species of the Spongillidae have no charac- 

 ters of higher than specific value. It is difficult to make out from 

 the literature of the family how far such a statement is justified. 

 However, the spicules of Spongilla tanganyikte possess 

 such characters that it is almost impossible to believe that they 

 have not a wider application. This sponge, considered from the 

 point of view of the skeleton, seems to present a certain amount 

 of affinity with a few species of the Spongillinje on the one 

 hand, and of the Lubomirskinse on the other. 



The megascleres of the greater number of species arrayed 

 under the sub-family Spongillinae are sharp-pointed, — that is, 

 they are either amphioxea or amphitornota. There are, how- 

 ever, a few species which possess spicules with rounded ends 

 that is, amphistrongyla. The species in question are Spon- 

 gilla nitens (Carter [3]), Spongilla bohmii (Hilgendorf 

 [5], and Spongilla loricata (Weltner [13]), to which may 

 be added Spongilla tanganyikse, now described for the first 



