20 U.S. NATIONAL MUSEUM BULLETIN 2 72 



Spongilla wagneri Potts, 1889 



Plate 1, figures 11-15 



Spongilla wagneri Potts, 1889, p. 7. — Smith, 1922, p. 106. — Eshleman, 1950, 

 p. 36. 



Material. — Several slides of sponges collected in eastern South 

 Carolina (Penney). 



Description. — Sponge, according to Potts (1889), forming thin 

 crusts without branches; surface greatly roughened, due to an abun- 

 dant occurrence of peripheral microscleres in dermal membrane. 

 Skeleton texture loose and open. Consistency of live sponge rather 

 brittle. 



Megascleres rather long and robust fusiform amphioxea, entirely 

 smooth; length range 144-270 n, width range 7-12 n. 



Microscleres excessively abundant both in dermal membrane and 

 inner symplasm ; they are long and slender amphioxea, slightly curved 

 and delicately pointed, entirely covered with spines; these are erect, 

 somewhat rounded at their extremities, and increase in length towards 

 the center of the spicule; length range 49-62 n, width range 2-4 /x. 



Gemmoscleres long and stout, moderately curved amphioxea, 

 entirely covered with stout, sharp, and recurved spines; these are 

 more numerous towards the extremities of the spicules where they 

 often form distinct "heads"; length range 48-75 n, width range 6-8 ju. 



Gemmules rather abundant in sponge, particularly within the 

 lower layers; according to Potts (1889) often hidden away within 

 the cavity of barnacles or among the coils of Serpiila upon which the 

 sponge has grown; they are large and spherical, ranging 470-610 n in 

 diameter ; pneumatic layer unusually strong, distinctly granular, very 

 irregular in thickness; outer gemmular membrane thin and produced 

 into a number of radiating thick lobes; gemmoscleres abundant, 

 embedded in this coat in an irregular manner, but displaying a 

 pronounced radial arrangement in the thicker pneumatic lobes; 

 foramen slightly elevated in order to reach the surface of the pneu- 

 matic layer, but not tubular. 



Distribution. — Apparently restricted to the coastline of the south- 

 eastern United States, ranging from Florida (Potts, Eshleman) to 

 Louisiana (Smith) and South Carolina; optimal habitat slightly to 

 strongly bracldsh waters. 



Color in life. — Recorded as whitish. 



Discussion. — Unfortunately, the present material consists of only a 

 few slides; therefore additional data on the consistency of the skeletal 

 meshwork and mode growth are not available. S. wagneri thus remains 

 a rather ill-known species in spite of its correct and sufficient original 

 description by Potts (1889). 



