1906.] OF THE THIRD TANGANYIKA EXPEDITION. 219 



from the Ugalla River, a tiibutary of the Malagarassi River flow- 

 ing into the lake, viz. S. bohmii Hilgendorf and >S'. nitens Cartel-. 

 The number of known species of Afi'ican Freshwater Sponges 

 is thus brought up to 19. 



The following is a list of the species referred to in this 

 paper : — 



Spoiigilla carteri Bowerbank. Victoria Nyanza. 



Spongilla moorei Evans. Tanganyika. 



Spongilla tanganyikce Evans. Tanganyika. 



Spongilla cunningtoni, sp. n. Tanganyika. 



Spongilla biseriata "Weltner. Nyasa.. 



Spongilla 7'ousselefAi, sp. n. Victoria Falls, Zambesi. 



Spongilla ? zamhesiana, sp. n. Victoria Falls, Zambesi. 



Ephydatia plumosa Carter var. bro^ooii, nov. var. White Nile. 



Spongilla cakteri Bowerbank. (Plate XV. figs. 1-4.) 



1848. Spongilla friabilis Lamarck, Carter, Ann. Mag. N. H. 

 (2) i. p. 310; 1849. Carter, ibid. (2) iv. p. 81. 



1863. Spongilla carteri Bowerbank, Proc. Zool. Soc. 1863, 

 p. 469. 



1887. Spongilla carteri Potts, Proc. Acad. N. S. Philadelphia, 

 1887, p. 194. 



There are two small specimens of this species, one of which 

 has been removed from a piece of rock, the other from a shell of 

 Aetheria. Unfortunately thei-e are no gemmules present, but the 

 characters of the surface and of the skeletal framework are those of 

 Bowerbank's species. Plate XV. figs. 2, 3, 4 represent the oxeas * 

 of specimens from the Victoria Nyanza, Bombay, and Mauritius 

 respectively ; it will be seen that the first (258 x 9*5 ji) is the 

 smallest and has abruptly pointed almost tornote ends. The 

 average size of the oxeas of the type specimen from Bombay is 

 287 X 11-75 fi and of the Mauritius specimen 349 x 18-5 fi. 

 The thin dermal membrane, perforated by groujDS of pores, sti-etches 

 between the sharp-pointed irregular conules formed by the ends 

 of the longitudinal main fibres. 



Localities.' -^wtobhe, Victoria Nyanza, shallow water. Bombay ; 

 Mauritius ; Calcutta ; Madui'a I. ; N. Java ; Lake Balaton, 

 Hungary. 



Spongilla moorei Evans. (Plate XV. figs. 5-9.) 



1899. Spongilla moorei Evans, Quart. Joiirn. Micr. Sci. vol. xli. 

 p. 472, pi. xxxvii. figs. 1-5, and pi. xxxviii. figs. 6-8. 



There are five specimens of this species from five localities in 

 Lake Tanganyika : three come from shallow water, and two from 

 about 10 fathoms. They are all in the form of thin crusts from 

 I to 1| mm. thick on stones and shells, and none of them attains 



* The terms " oxea," " fcomote," " strongyle," clearly defined by SoUas in 1888 

 (' Challenger ' Rep. Tetractinellida, pp. liv, 1 v), seem to me preferable to " amphioxea," 

 &3., because, in addition to having- clainm of prioritj'' and brevity, they leave no doubt 

 as to the form of the spicules they are intended to designate. 



