40 U.S. NATIONAL MUSEUM BULLETIN 2 72 



must remain highly speculative. A spongiliid closely resembling E. 

 potamolepis has recently been found in Australia (Racek, MS.) and 

 will be subjected to a detailed morphological study. 



Genus Stratospongilla Annandale, 1909, i-edefined 



Spongilla {Stratospongilla) Annandale, 1909e, p. 561; 1911c, p. 122; 1912d, p. 385; 

 1914, p. 245; 1918a, p. 212; 1919a. p. 160.— Annandale and Kawamura, 1916, 

 p. 1.— Weltner, 1913, p. 481.— Stephens, 1919, p. 99.— Gee, 1931c, p. 34; 

 1932c, p. 36.— Arndt, 1936, p. 14. 



Type species. — Spongilla bombayensis Carter, 1882. 



Definition. — Megascleres usually stout amphioxea or amjjhistron- 

 gyla, smooth or roughened by minute and irregular projections. 



Microscleres, comparable with the "flesh spicules" of other genera, 

 usually present in dermal membrane and vicinity of the gemmules; 

 if present, they invariably are short and slender amphioxea, almost 

 straight, covered with relatively long and irregular spines. 



Gemmoscleres more or less strongly bent amphistrongyles, covered 

 with minute spines of unequal size, or slightly curved spin ed amphioxea, 

 or a combination of both. 



Gemmules large and spherical, as a rule with a flattened base, 

 aggregated in the basal membrane of the sponge, usually firmly 

 adherent to the substratum; occasionally free in inner symplasm of 

 sponge; pneumatic layer without noticeable air spaces, often poorly 

 developed or altogether absent, situated entirely outside the layer of 

 gemmoscleres; the latter embedded tangentially in the outer gemmular 

 membrane, in one or more compact layers; foramen or foramina 

 always tubular, tube either short and straight, or long and recvirved. 



Sponge usually forming shallow cushions of moderate size; coloration 

 often a bright gTeen. Consistency ranging from hard to almost stony 

 hard. 



Apparently restricted to the tropics, with greatest abundance in 

 Asia and Africa; not yet recorded from tropical Australia. 



Discussion. — Stratospongilla, originally introduced by Annandale 

 (1909e) as a subgenus of Spongilla and retained as such until 

 the present, is herewith elevated to full generic rank. It is most 

 closely related to the genus Corvospongilla, with which it shares the 

 peculiar characteristics of the gemmules, as well as features of general 

 morphology and distribution, but from which it differs by the absence 

 of microbirotulates as free microscleres. 



Apart from the species complexes discussed in dealing with S. 

 bombayensis, S, sumatrana, S. indica, S. gravelyi, S. rousseletii, S. 

 schubotzi, and S. gilsoni, material of which was available for the 

 present study, two species of somewhat doubtful generic relationships 

 are also often referred to the genus Stratospongilla, S. dementis 



