ECHINODERMATA. 
76 § 
every one working at tlie subject. The first portion is on West-In- 
dian Ecliinidae : a list of species known on the more southern 
coasts of the United States, of Brazil, and the Antilles is given 
(pp. 1-58). The distribution in space of the genera of recent 
Echinidse'is given at p. 135. We give a few of the more im- 
portant matters referred to : — 
Cidaris mctidaria and C. trihtdoides, although often confounded and some- 
what like each other, are sufficiently distinct ; the former comes from the 
Antilles, the latter from the Red Sea (p. 11). 
Ileliocidaris casteJnaudi (Hup^) is only a variety of Echinometra lucimter, 
p. 18. 
Psilechimis, g. n., p. 25, is proposed for Echinus excavatus (Blainv.) and E, 
variegatus (Lmck.) which do not differ specifically (p. 26). It is characterized 
by the great depth of the scales on the peristome and by the partial 
nakedness of the ambulacral and interambulacral area on the upper surface 
of the corona. 
Jleliechinus goiddii (Girard) = ventricosus (p. 27). 3Ielehosis 
(Gir.) must be erased from the list of genera ; M. mirahilis is only a species 
of Sahnacis (p. 127). 
Echinocidaris. Two species only of this genus are known in the Mediter- 
ranean and Atlantic, viz. E. ccquituherculata of the former, and E. punctidatay 
Florida (p. 31). 
Tolynstcr (Mich.) {Michclinia, Duj. et Ilup(5) is identical with Laganumy 
and probably P. elegans is only L. Umneurii (p. 38). 
Pumphia is not to be distinguished from Laganum by any external cha- 
racters (p. 38). 
3Iell{ta. But two species are found on the coast of South America : 31. 
pentapora (Gm.) = 31. testudinata, 31. longijissa, 31. nummtdariaj and 31. 
ampla\ M.hcxapora (Gm.) = AT. and ilf. lohata (p. 39). 
Encope. All the species described as occurring on the tropical shores of 
America are reduced to one, E. emarginatay Leske, the several species of Gray, 
Desor, and Agassiz being refen-ed to as local varieties (p. 43). The dif- 
ference between this genus and 3Iellita is well pointed out (p. 47). 
Brissus ventricosus, Lmk. {B. panis, Grube), belongs to the genus 3Ieomay 
Gr. (p. 62). 
Plagionotus dcsorii is not to be distinguished from P. pecim'alis, nor 3Ioera 
lacliesis from 31. atropos (p. 54). 
Cassidulus caribbcearum has some of the characters of a Cassidulus and some 
of those of a Bhynchopggus ; hence it must either be consigned to a new genus 
or those two genera must be united (p. 69). 
The second part treats of species found on the western coast of 
Central America (p. 61). 
Echinocidaris longisjmia, sp. n., p. 62, Panama; Clypea^ter riisei, sp. n., 
p. 64, Panama ; Agassizia ovulum, sp. n., p. 66, Boccones. 
Cidaris tuharia (Link.). This species, according to Lamarck’s description, 
is evidently a Goniocidaris (Ag,, Des.), probably G. gei'anioidcs of these 
authors ; but it is not easy to reconcile this view with the description in the 
* Catalogue Raisonn^ ’ (p. 69). 
