238 ^^- AXNANDALE. 



Part 1. A Systematie Aceonnt of tlie Colleetion. 



Gen. Spongilla, Lamark. 



Subgen. Eunapius, Gray. 



The subgenus Eunajmis, whicli is separated from Euspongilla by the 

 well-defined polygonal air-spaces in the Investment of its gemmules, is 

 represented in Tropical Al'rica by several species. Dr. Michaelsen's 

 colleetion includes specimens of yet another new one. 



Tho following key tho the African species may be useful: 



Key the to African spezies of Ennaxnus: 



I. Gemmule-spicules smooth. 



A. Gemmules single and free in substance of sponge S. carteri.^) 



B. Gemmules forming a pavement-layer at base of 



sponge S. aetheriae. 



II. Gemmule-spicules spiny. 



A. Gemmules single and free in substance of sponge. 



1. Skeleton-spicules stout, amphistrongylous S. nitens. 



2. Skeleton-spicules slender, sharply pointed S. michaelseni. 



B. Gemmvües forming a pavement-layer at base of 



sponge. 



1. Gemmule-spicules amphioxous . . . . S. ambigua. 



2. Gemmule-spicules amphistrongylous . . S. permiocta. 



Spongilla nitens, Carter, yar. 



Carter, Ann. Mag, Nat. Hist. (5) VII, p. 89, pl. V, fig. 3, a— k, & pl. VI. % 18 (1881); 

 Weltner, „Die Coelenteraten und Schwämme des Süßen Wassers Ost-Afrikas" in Möbius, 

 Ost- Afrika IV, p. 3, tigs. (1898), and „Siil3wasserschwämme (Spongillidae) der Deutschen 

 Zentralafrika-Expedition 1907—1908 in Wiss. Ergeb. d. Deutsch. Zentral- Afrika-Exp. IV 

 (Zool. ii). Lief. 12, p. 475. 



This sponge is represented in Dr. Michaelsen's colleetion by four 

 cushion-shaped masses detached from stones; the largest of the four is about 

 35 X 28 mm in diameter. The external surface of both is ornameuted with 

 numerous sharp slender projections of irregulär outline, as appears to be 

 usual in the species. Although hard, the sponge is very brittle. The 

 skeleton-spicules measure on an average 0,363 mm by 0,026 mm, being thus 

 considerably more slender than in the tyj)e. The gemmules are abundant 

 and fuUy devcloped. 



') Doubtfnlly African, see p. 24.Ö. 



