150 U.S. NATIONAL MUSEUM BULLETIN 272 



Material. — S. vesparium: Slide of syntype (N. Gist Gee) ; material 

 and slides from Kalimantan (Borneo) ; T. pottsi: Slides of syntype 

 (MCB); M. lissostrongyla: Fraction and slides of type (MCB); 

 numerous specimens from various African localities (MCB). 



Description. — Sponge forming large bulbous growths, resembling 

 the structure of a wasp nest; surface strongly reticulate and hispid; 

 oscula moderately large but inconspicuous; dermal membrane closely 

 adhering to symplasm. Skeleton consisting of thick and strong radial 

 spicule fibers, arising perpendicularly from the base, and of somewhat 

 slimmer transverse fibers; both forming a very firm and compact 

 network of wide meshes. Consistency of dry sponge very rigid but 

 brittle. 



Megascleres cylindrical, slightly curved, and entirely smooth amphi- 

 strongyla of greatly varying lengths, ranging 150-220 n, width range 

 11-16 fx. 



Microscleres almost straight, fusiform, and sharply pointed amphi- 

 oxea, covered with small granules at then- tips and bearing a group of 

 larger spines in their central portion; length range 54-67 n, \\ddth 

 range 2-3 /x. 



Gemmoscleres tubelliform, lower rotule almost invariably circular 

 with an entire, slightly recurved margin; shaft usually irregularly 

 covered with large tubercles or blunt spines; terminal knob either 

 smoothly rounded, or bearing a small number of recurved minute 

 spines; length range 35-55 ju, diameter or rotule 18-20 n, of knob 

 6-8 ju, width of shaft 3 fi. 



Gemmules scattered through the skeletal meshwork, spherical, 

 ranging in diameter 400-500 fx] pneumatic layer feebly developed 

 and comparatively thin, consisting of larger air spaces; gemmoscleres 

 embedded in this layer in a manner typical for the genus; foramen 

 produced into a short and straight tubule. 



Distribution. — Known from Borneo (Kalimantan), Indonesia, 

 and central Africa, distribution apparently discontinuous. 



Color in life. — Not yet reliably recorded; dry sponge usually dark 

 brown to almost black. 



Discussion. — The curious fact that von Martens' (1868) paper had 

 been overlooked by all his contemporary workers and by many sub- 

 sequent authors led to the erection of Tubella pottsi by Weltner (1895), 

 which now must be considered identical with M. vesparia. Further 

 confusion resulted from the failure of revising authors (Annandale, 

 Gee) to recognize free microscleres in the type slides reexamined where 

 they are very rare but nevertheless present. This contributed to the 

 retention of Carter's (1881a) heterogeneous generic name Tubella for 

 those species apparently without microscleres and the introduction of 



