8 
CATALOGUE OF ECHINIDA. 
Zooph. 299 ; Desmovl. Echin , 214 ; Agassiz, Prod. 20; Mem. 
Soc. Neufch. 187. 
Echinanthus ambigena, Gray, Ann. Phil. 1825, 5. 
Clypeaster placunarius, LamJc. Hist. iii. 12, Ed. 2, iii. ; Agassiz 
& Desor, ]. c. 11. 
Echinarachnius placunarius, Agassiz, Prod. 
Ecliinodiscus placunaria, Blainv. I). S. N. lx. 199 ; Zooph. 218. 
Scutella placunarius, Lamk. Hist. 12, Ed. 2, iii. 285 ; Dedong , 
Eth. ii. 678 ; Desmoul. Tab. 228. 
Hab. Red sea. Ruppett. 
a. Not good state, without spines. Red Sea. Presented 
by J. Burton, Esq. 
b. Covered with spines ; edge thick ; shell heavy. Red Sea. 
c. Not good state. Red Sea. 
d. With a few spines ; ambulacral petal rather narrow. 
Red Sea 1 
Yar. 1. Crown rather higher ; space between petal of ambu- 
lacra very convex. 
e. f. Without spines ; the space within the petal of the 
ambulacra very convex. Red Sea 1 
g. Without spines ; the middle of the back rather high ; 
the space between the petal very convex. Muscat. 
Yar. 2. Edge rather rounded. 
h. With some of the spines. Red Sea. 
11. Echinanthus parvus. 
Small (smallest known). 
Clypeaster parvus, Duchassaigne ; Bull,. Tran. Soc. Geol. 1847 ; 
Agassiz Desor , 1. c. 130. 
Hab. Guadaloupe, in white tufa. 
See also Rumph., t. 14, f. c. ; Placenta, Van Phelsum, 25; 
Echinanthus humilis, Leske, 187, n. 47 ; Clypeaster Rumphii, 
Desmovl. Tab , Syn. 216. 
b. Ambulacral petals narrow, open at the end * 
2. Laganum. 
Shell depressed, pentagonal, sub-pentagonal, or ovoide, trun- 
cated behind, rostrated in front ; ambulacral petals elongate, 
narrow, and only slightly rounded at the end ; ovavial pores 
four or five, contiguous to the madreporiform plate ; cavity 
simple, except near the margin ; mouth small, open to the 
level of the shell ; jaws large, rather flat ; vent below. 
Placenta lagena, Klein , Echin . 
