CATALOGUE OF ECHINIDA. 
31 
five or ten sides, with a thin simple edge ; jaws none ; vent 
posterior, inferior (in fossil, rarely dorsal; ambulacra in a 
single series of double pores ; series parallel ; ovarial plates five ; 
ocellar plates five, intercolated with the former. 
Galeritidse, part., Gray , Ann. Phil. 1825, 6. 
Fibula, Klein. 
Clypeasteroidea (Galeritae), Agassiz; Desor , Monag. Galerites , 
iii. 89. 
Des Cassidulides (des Echinoneides), Agassiz <$> Desor. t Ann. Sci. 
Nat. 1847, 148. 
Echin. Centrostomes (part.), Blainv. Diet. Sci. Nat. lx. ; Deslong. 
in Lamk. Hist. iii. 272. 
Mesostoma, part., Latr. Fam,. R. A. 533, 1825. 
Clypeasteroidea a Galeritas, Agassiz; Bronn, Gesch. Nat. 193. 
E. Paracentrostomes edentes, Blainv. D. S. N lx. 188. 
Catocysti emmesostomi, part., Van Phelsum. 
The body is formed, like the true Echinidce , of twenty ver- 
tical bands, the ambulacral bands being the narrowest. The 
sutures are not so distinctly sinuous as in Echinidce. Gray , 
Ann. Phil. 1825. 
A. Tubercles mammillated ', but not 'perforated or crenulated . — 
Echinoneina. 
1. Echinoneus. 
Shell thin, elongate, subcylindrical ; tubercles very numerous 
placed in more or less regular series; mammillate but not 
crenulated or perforated, and intermixed with transparent 
glassy tubercles ; mouth oblique, somewhat five-sided ; vent 
very large, elongate, inferior between mouth, and hinder mar- 
gin ; closed by a number of small plates ; ovarial pores four, very 
close, at the apex of the inter-ambulacral area ; madrepori- 
form plate central, irregular. Their intestines are filled with 
fragments of corals, or with foraminifera. 
Echinoneus (Egelschuitje) Van Phelsum ; Leske ap. Klein ; 
Lamarck, Syst. 347, 1811 ; Desmoul. Etud. Echin. i. 41 ; 
Desor, Monag. Galerites , i. 40, 91 ; Agassiz Ac Desor , Ann. 
Sci. Nat. 1847, 148. 
Echinonseus, a. ; Blainv. D. S. N. lx. 193. 
Echinonaus, Koenig ; Gray, Ann. Phil. 1825, 7. 
Echinoceni, part., Breynius. 
Galerites, sp., Desmoulin , Etud. Ech\n. i. 25. 
Agassiz divides the tubercles into three kinds ; 1, prin- 
