22 
granulae are disposed. The mouth is reniform, placed crossways, at 
the broadest extremity. The anus is of a roundish oval figure, and 
is near to the narrow extremity. The spine, which gives name to 
the species, runs down from the vertex and along the narrower end, 
and becomes attached to the higher edge of the anus. Plate II. Fig. 
4, is a species from the Kentish chalk-pits. 
E. ovatus, Lesk. Galea ivagrica, vertice nuda, Klein, differs from 
the former species in being more depressed in its circumference, 
being of a rounder oval ; and in being without the crest-like ridge 
which runs along the back of the other species. Another species, 
Echinocorytes quaterradiatus, has been formed from an echinite 
figured and described by Melle, Tab. i. Fig. 7 ; but I suspect the 
absence of the fifth ray has proceeded from the omission of the 
engraver, since, in the remarks on this fossil which are made by 
Melle, at some length, this remarkable character is not noticed. 
Among the smaller echinocorytes, most of which are mere nuclei, 
certain particulars are observable, which, though hardly sufficient to 
distinguish them as varieties, still deserve notice. A variety is marked 
by Leske, Tab. xvi. c. d. Klein, Galeola papillosa ; in which, as he 
observes, the papillae evidently result from the silicious matter which 
filled the foramina of the shell still continuing, whilst the shell which 
surrounded them is removed. Another, Tab. xvn. a. h. Klein, is 
named G. undosa, from the waving lines on its surface, formed by 
the silicious matter having insinuated itself between the edges of the 
plates forming the shell. 
Part of a remarkable cast of a galeated echinite is shown Plate II. 
Fig. 9, said to be from France. Although this fossil is hollow, and 
retains such strong markings of the shell, it can still be only con- 
sidered as a cast. Its substance appears to be pyrites of iron, which 
has suffered some decomposition, and has been since frosted over 
with minute quartz crystals. Its matrix appears to have been chalk, 
some of this substance being yet adherent to it on several parts. Its 
