CATALOGUE OF ECHINIDA. 
27 
** Posterior central perforation round , near the margin , beyond 
the end of hinder ambulacra. 
6. Encope Stokesii. 
I Sub-circular ; the posterior central slit oblong, or roundish, 
broad ; the slits all open, broad, and rounded at the inner 
end. 
Encope Stokesii, Agassiz . , Mon. Scutelles, 59, 147, t. 6, a. 
f. 1-8 ; Agassiz & Desor, 1. c. 137. 
Hab. Guayaquil. 
a, b , c, d, e. Without spines. Guayaquil. Presented by 
R. B. Hinds, Esq. 
d. Without spine ; posterior perforation small, narrow. 
II. Ambulacral pores not united by a cross groove , round , and 
quite isolated. — Fistularina. 
11. Moulinsia. 
Shell thin, depressed, oval ; edge thin, festooned ; surface 
covered with very apparent tubercles ; ambulacral petals even 
at the ends ; the pores not conjugated by a transverse groove ; 
vent inferior ; internal cavity ? 
Moulinsia, Agassiz , Mon. Echin. ii. 139, 151 ; Agassiz & Besov , 
Ann. Sci. Mat. 1847, 139. 
1. Moulinsia cassidulina. 
Scutella cassidulina, Desmovl. Tab. Syn. 232. 
Moulinsia cassidulina, Agassiz, Mon. ScuteUes, ii. 139, t. 22, f. 1-6, 
151 ; Agassiz & Desor , 1. c. 139. 
Hab. Martinique, Bang. Mus. Paris. 
12. Echinocyamus. 
Shell thick, flat, sub-circular, elliptical, or somewhat five- 
sided ; edge rounded ; cavity with radiating internal septa ; 
ambulacral petals elongate, open at the ends ; pores not con- 
jugated ; mouth round ; jaws high ; vent inferior, small, 
circular, just intermedia! between the mouth and the hinder 
edge ; genital pores four ; tubercles rather large ; spines elon- 
I gate, subulate. 
Echinocyamus, VanPhelsum; Leske; Klein, Echid.; Gray, Ann. 
Phil. 1825, 6; Fleminq , Brit. An. 481, 1828; Blainv. Diet. 
S. N. lx. 194. 
' Fibularia, Lamk. Hist. 1816 ; Agassiz, Prod. Ann. N. H. i. 303 ; 
Mon. ScuteUes, i. 125, 150; Agassiz & Desor, Ann. Sci. Nat. 
1847, 140. 
