THE SPONGES (PORIFERA) 315 



SO (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. 

 1909a. 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. 



1911a. 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; pl- 5-6. 

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



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



