122 U.S. NATIONAL MUSEUM BULLETIN 2 72 



from all species of Ephydatia, as here redefined, to such an extent 

 that it cannot possibly be considered congeneric. On the other hand, 

 although displaying close affinities to most species of Heteromeyenia, 

 and particularly to Dosilia, the presence of homogeneous gemmoscleres 

 and the absence of asters from the latter genus would eliminate it 

 from belonging to the former. In order to demonstrate the con- 

 spicuous differences of this SE Asian and Australian species from all 

 other spongillid genera, the erection of a new genus became inevitable. 

 Although the writer intended to use this genus in his forthcoming 

 revision of all Australian Spongillidae, the scope of the present work 

 made it imperative to introduce it at this stage. 



Umborotula bogorensis (Weber, 1890) 



Plate 11, figures 1, 18, 19 



Ephydatia bogorensis Weber, 1890, p. 33. — Weltner, 1895, p. 114. — Annandale 

 1911c, p. 54; 1918a, p. 201.— Gee and Wu, 1925b, p. 393.— Vorstman, 1927, 

 p. 184.— Gee, 1926c, p. 110; 1927a, p. 1; 1927b, p. 61; 1928, p. 225; 1929d, 

 p. 297; 1930a, p. 84; 1930b, p. 170; 1930e, p. 27; 1931e, p. 34; 1932a, p. 449; 

 1932c, p. 28.— Arndt, 1932c, p. 564. 



Ephydatia blembingia Evans, 1901, p. 71. — Annandale, 1907a, p. 269; 1911c, p. 54; 

 1918a, p. 207.— Gee, 1930a, p. 90. 



Ephydatia bogorensis var. blembingia Gee, 193 le, p. 34; 1932a, p. 449; 1932g, 

 p. 308; 1932c, p. 28.— Suvatti, 1950, p. 3. 



Meyenia bogorensis Penney, 1960, p. 46. 



Meyenia bogorensis var. blembingia Penney, 1960, p. 46. 



Material. — Slides of types of E. bogorensis (AmstM) and E. 

 blembingia (BM), and specimens of U. bogorensis from Soochow, 

 China, and Java. 



Description. — Sponge forming circular or irregular crusts or 

 nodules of minute size on aquatic plants; surface shghtly hispid due 

 to projection of spicule fibers through dermal membrane; oscula 

 small and inconspicuous. Skeleton consisting of an open meshwork 

 formed of spicule fibers bound together by only small amounts of 

 spongin. Consistency of Uve sponge very soft and fragile. 



Megascleres feebly curved and slender amphioxea, which are 

 fusiform and covered, with the exception of their tips, with very 

 minute conical spines; length range 240-370 n, width range 13-16 n. 



Microscleres absent. 



Gemmoscleres, when fully developed, birotulates with compara- 

 tively long and spiny shafts, and with equal umbonate rotules whose 

 margins are distinctly recurved and regularly incised; length range 

 60-78 n, width range of shafts 3-4 n, diameter of rotules 22-27 ju. 



Gemmules very scarce and scattered throughout meshwork of 

 sponge, spherical, ranging in diameter 450-600 /i; pneumatic coat 

 well developed, consisting of very minute air spaces, and granular; 



