THE SPONGES (PORIFERA) 



34 (33) Birotulates many times longer than diameter of rotules. 



Ephydatia craterijormis (Potts) 1882. 



Sponge encrusting, thin. Gemmules small, white, very numerous. Granular crust of gem- 

 mules extremely thick, the foraminal tubes in a crater-like depression. Skeleton spicules 

 slender, gradually pointed, sparsely microspined. Birotulates very long and slender, shafts 

 abundantly spined. Rotules of three to six short recurved hooks. In shallow water, rapidly 

 flowing; Schuylkill and Delaware Rivers, Pennsylvania. Found by 

 F. Smith in the Sangamon River, 111, 



Annandale places this species in Spongilla owing to the imperfect 

 development of the rotules (see Fauna of British India; Fresh-water 

 Sponges, IQII, p. 83). 



Bowerbank, in 1863, described, under the name of Spongilla bail- 

 eyi, a sponge from a stream at Canterbury Road, West Point, N. Y., 

 which may be the same as this species. The description is too in- 

 complete to allow of an accurate determination. His description is 

 quoted by Potts (1887: 227) 



FIG. 572. Spicules of Ephydatia crateriformis. Three types of spicules 

 figured here: slender microspined skeleton spicules; mature gemmule birot- 

 ulates with short hooked rays; supposed immature forms. X 100. (After 

 Potts.) 



35 (20, 36) Dermal spicules, minute birotulates. 



Ephydatia everetti (Mills) 1884. 



Sponge green consisting entirely of slender filaments, little more 

 than a sixteenth of an inch in diameter. Gemmules few, but usu- 

 ally large with a thick crust. Skeleton spicules slender, cylindrical, 

 smooth. Dermal spicules, minute birotulates with slender cylindrical 

 shafts and cap-like rotules notched into five or six hooks. Gemmule 

 birotulates long and club- like; shafts smooth and slender; rotules 

 formed of five or six stout, recurved, acuminate hooks. In cold 

 water, Berkshire County, Mass., and Nova Scotia. 



FIG. 573. Spicules of Ephydatia everetti. Four types of spicules figured 

 here: smooth, skeleton spicules; gemmule birotulates; end view of rotule 

 formed of hooked rays; minute dermal birotulates. X 100. (After Potts.) 



v\\ 



\ 



36 (20, 35) Dermal spicules stellate Dosilia Gray. 



Only species yet reported in the United States. 



Dosilia palmeri (Potts) 1885. 



Sponge massive, subspherical, lobate. Skeleton spicules sparsely 

 microspined, curved, gradually pointed. Dermal spicules star- 

 shaped, consisting of a variable number of arms of various lengths, 

 radiating from a large smooth globular body; arms spined through- 

 out. Gemmule birotulates with long spined shafts, rotules notched. 

 From Colorado River, 60 miles below Fort Yuma, attached to 

 pendent branches flooded by spring freshets. 



In the opinion of Annandale, Potts' yar. palmeri is a different 

 species from Carter's plumosa from India. He has seen types of 

 both and is confident both belong to Dosilia. 



FIG. 574. Spicules of Dosilia palmeri. Five types of spicules figured 

 here: robust, microspined skeleton spicule: spined gemmule birotulates; 

 rotules of same, irregularly notched; substellate dermal spicules; imperfect 

 form of same with only two rays; amorphous "Scotch terrier" forms. 

 X ioo. (After Potts.) 



37 (15) Gemmule birotulates of two distinct classes , . . . 38 



38(41) Dermal spicules stellate A steromeyenia Annandale . . 39 



Spongillidae with birotulate gemmule spicules of two distinct types and free microscleres in 

 the form of anthasters. 



