314 



FRESH-WATER BIOLOGY 



48 (49, 50) Foraminal tubule very long and slender, tendrils short, irregu- 

 larly waving Carterius tubisperma Mills 1881. 



Sponge massive. Gemmules numerous. Length of foraminal tubule one-half to once diam- 

 eter of gemmule. Skeleton spicules rather slender, gradually pointed, sparsely spined. Der- 

 mal spicules long, slender, entirely spined. Gemmule birotulates abundant, irregular in length, 

 suggesting genus Heteromeyenia, shaft smooth or with one or more spines, rotules arched, rays 

 numerous, long, incurved. Assigned by Annandale to genus Heteromeyenia. In Niagara River, 

 N. Y., Massachusetts, and Michigan. 



FIG. 581. Carterius tubisperma. A. Partial section of gemmule; (a), Foraminal aperture prolonged 

 into a long tubule flaring and funnel-shaped at its extremity and divided into several short tendrils (d) 

 or cirrous appendages, (ft) , birotulate spicules. X 50. (After Potts.) B. Three types of spicules figured 

 here: skeleton spicules; gemmule birotulates; face of rotule; long spined slender dermal acerates. X 100. 

 (After Potts.) 



49 (48, 50) Foraminal tubule shorter; tendrils, one or two, enveloping the 

 tubule Carterius latitenta Potts 1881. 



Sponge often encrusting stones in rapidly running water. Gemmules numerous. Cirrous ap- 

 pendages at first flat and ribbon-like, becoming slender and rounded, and occasionally subdivid- 

 ing. Skeleton spicules smooth: or sparsely microspined, gradually pointed. Dermal spicules 

 long, entirely spined. Birotulates stout, shafts with numerous long pointed spines. Rays of 

 rotules deeply cut and sometimes recurved. Annandale believes this and the following species 

 should be assigned to Ephydatia. In Pennsylvania, western New York, and Illinois River. 



FIG. 582. Carterius latitenta. A. Partial section of gemmule; (a), foraminal tubule short; (b), birotu- 

 late spicules; (d), one or two long and broad, ribbon-like cirrous appendages. Xao. (After Potts.) B. 

 Three types of spicules figured here: skeleton spicules; gemmule birotulates variable in length; face of 

 rotule; spined dermals. Xioo. (After Potts.) 



