THE SPONGES (PORIFERA) 315 



50 (48, 49) Foraminal tubule still shorter; tendrils, three to five, very long 

 and slender Carterius tenosperma Potts 1880. 



Sponge forming irregular masses creeping upon and around water plants and roots, less fre- 

 quently encrusting stones. Gemmules rather numerous. Foraminal tubules about one-fourth 

 the diameter of the gemmules. Tendrils as much as half an inch long. Skeleton spicules slen- 

 der, very sparsely microspined. gradually pointed. Dermal spicules slender, nearly straight, 

 entirely spined. Birotulates with cylindrical shafts, abundantly spined, rotules often irregular. 

 New Jersey and Eastern Pennsylvania. 



FIG. 583. Carterius tenosperma. A. Section of gemmule, (a), short tubule; (d), long, slender cirrous 

 appendages. X35- B. Three types of spicules: skeleton spicules; spined gemmule birotulates with 

 burr-like rotules; ends of same; long, spinous, acerate dermal spicules. X 100. (After Potts.) 



IMPORTANT REFERENCES ON FRESH-WATER SPONGES 



ANNANDALE, N. 1909. Report on a Collection of Fresh-water Sponges from 



Japan. Annot. Zool. Japon., 7: 105-112, pi. 2. 



iQ09a. Fresh-water Sponges in the Collection of the United States Na- 

 tional Museum. Part II. Specimens from North and South America. 

 Proc. U. S. Nat. Mus., 37: 401-406. 



1910. Fresh-water Sponges in the Collection of the United States National 

 Museum. Part IV. Note on the Fresh-water Sponge Ephydatiajaponica, 

 and its Allies. Proc. U. S. Nat. Mus., 38: 649-650. 



1911. Fresh- water Sponges in the Collection of the United States National 

 Museum. Part V. A New Genus proposed, with Heteromeyenia radio- 

 spiculata Mills as Type. Proc. U. S. Nat. Mus., 40: 593-594. 



191 la. Fresh-water Sponges, Hydroids and Polyzoa. Fauna British India. 



251 PP-, 5 pl. 

 CARTER, H. J. 1881. History and Classification of the Known Species of 



Spongilla. Ann. Mag. Nat. Hist., (5), 7: 77-107, pl. 5-6. 

 POTTS, EDWARD. 1883. Our Fresh- water Sponges. Amer. Nat., 17: 1293-6. 

 1887. Fresh-water Sponges; a Monograph. Proc. Acad. Nat. Sci., Phila., 



39: 158-279, pl. 5-12. 

 1890. Fresh- water Sponges. Microscope, 10: 140-143, 161-163, 193- 



196, 257-263, 307-310; Pi- 5-6- 

 WELTNER, W. 1895. Spongillidenstudien III. Katalog und Verbreitung der 



bekannten Siisswasserchwamme. Arch. f. Naturges., (pt. I), 61: 114-144. 



