550 ECHINONIDAE. 



ECHINONIDAE 



Subfamily Echinonidae Agass., 184 7, C. R. Ann. Sc. Nat., Vli. 147. 

 (See Part II. p. 332.) 



ECHINONEUS. 



Echinoneus Van Phi is.. 1774, Brief. 

 (Sn- Part II. p. 332.) 



Echinoneus cyclostomus 



Echinoneus cyclostomus Leske, 177s. Ki.. Add., p. 173. 



PL XIV. f. 6-8; PL XIV". f. 5-10. 



A large, denuded specimen, measuring one and a half inches in its longest 

 diameter, was of a dark brown color; the poriferous zones extending along 

 the test as darker narrow lines, mid the primary tubercles being prominent 

 by their yellow color. In this specimen the anal and buccal membranes were 

 preserved entire. The buccal membrane was entirely paved by small, irregu- 

 larly shaped plates, covering the whole surface, and leaving but a small open- 

 ing in the centre. — the elliptical mouth: the plates diminished in size 

 towards the oral opening: there were no less than twenty-six plates in the 

 circle adjoining the test. Covering the anal membrane, there were four 

 large plates extending on each side of the pear-shaped anus, the rest of the 

 membrane being covered with smaller plates : the anus was placed near the 

 blunt (posterior) extremity of the anal opening. For a comparison between 

 the two species of Echinoneus see Part 11. p. 333. 



Australia ; Kingsmills Islands ; Zanzibar. 



Echinoneus semilunaris 



Echinus semilunaris Gmel., 1788, Lixx. Syst. X*nt. 

 ! Echinoneus semilunaris Lame., 1816, An. s. Y<-rt.. p. 1ft. 

 (See Part II. p. 333.) 



PL XIV. f. 1-5; PL XXXVIII. f. 26. 



Florida ; AVest India Islands. 



