20 
CATALOGUE OF ECHINIDA. 
a. With two posterior perforations. 
1. Echinodiscus bifora. 
The hinder slits linear, elongate, very diverging ; the straight 
part of the hinder end wider than the middle of the front 
edge. 
Scutella bifora, Lamk. Hist. iii. 281 ; Agass. Prod. 388. 
Echinus biforis, Gmelin , S. N. 3188, part. 
Echinoglycus irregularis, Van Phelsum , 35, part. 
Echinodiscus, Knorr. Belie. Nat. i. 92, t. d. 1, f. 1. 
Scutella bilinearifora, Besmoulin, Tab. Syn. 226. 
Echinodiscus bifora, Gray, Ann. Phil. 1825, 6. 
Lobophora bifora, Agassiz , Mon. Seutelles, ii. 64, 147, t. 12 ; 
Agassiz & Besor , 1. c. 136. 
Hab. Madagascar, Red Sea. 
a, h. Adult. Red Sea. Presented by Major Macdonald. 
c. Half grown. 
d. Red sea. Presented by J. E. Gray, Esq. 
e. f. Red Sea. Presented by Sir J. Gardner Wilkinson, 
g, h. Indian Ocean. 
2. Echinodiscus truncata. 
The hinder slits diverging ; the straight part of the hinder 
end not so wide as the middle of the front. 
Scutella bifora, var. 2, Lamk. Hist. iii. 281 ; E. M. t. 147, 
f. 7, 8 ; Beslong. E. M. ii. 676 ; Blainv. B. S. N. xlviii. 222. 
Scutella bifora, Besmovl. Tab. Syn. 226. 
Scutella biforis, Blainv. B. S. N. lx. 200 ; Zooph. 200. 
Echinus biforis, part, Gmelin , S. N. 3188. 
Placenta (Mellita) laevis, Klein edit . Leske , 25, t. 21, f. A. b. ; 
Klein, Gall. § 81, 90, t. 11, f. b. 
Echinodiscus biperforatus, Leske ap. Klein , 296. 
Echinodiscus, Midler , Bel. Nat. i. 92, t. d. 1, f. 15. 
Pain d’epice a deux fentes, Bavilla , Cat. i. 423, n. 955. 
Lobophora truncata, Agassiz, Mon. Scutelles, 66, t. 11, f. 11, 16, 
147 ; Agassiz & Besor , 1. c. 136. 
Hab. 1 
a. Broken. 
3. Echinodiscus tenuissima. 
Shell very flat, with two very small lunules, corresponding 
to the hinder pair of ambulacra. 
Lobophora tenuissima, Agassiz & Besor, 1. c. 136. 
Hab. Waigron, Lesson. Mus. Paris. 
