THE TANGANYIKA PROBLEM. 
3 21 
(B) The Spicules. — It is generally stated that the skeletal 
spicules of the several species of the Spongillidse have no 
characters 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 
tanganyika possess such characters that it is almost im- 
possible 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 Spongillinse 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, 
however, a few species which possess spicules with rounded 
ends, that is, amphistrongyla. The species in question are 
Spongilla nitens (Carter), Spongilla bohmii (Hilgendorf) 
and Spongilla loricata (Weltner), to which may be added 
Spongilla tanganyika, now described for the first time. 
Spongilla tanganyika, therefore, seems to be more closely 
related to these species, so far as the characters of the 
skeleton are concerned, than to any other species of the 
Spongillinae. Of the three specie named above it appears 
to present closer affinity with Spongilla bohmii than with 
either of the other two, for in Spongilla nitens and in Spon- 
gilla loricata the amphistrongyla are smooth, while in both 
Spongilla bohmii and Spongilla tanganyika they are spiny. 
In the former the spines are more thickly set at the end, 
which is a special feature of the megascleres of some species 
of the Lubomirskinae, and which may point to a certain 
amount of affinity in that direction, while in the latter they 
are evenly distributed over the whole spicule. In Spongilla 
bohmii the megascleres are curved as in Spongilla nitens , 
