164 EOCENE MOLLUSCA. 
Though this species is said to be rare in France, it does not appear to be so in 
England ; it seems to have taken the place of Cr. ¢rigonata ; this latter, although so 
abundant there, has not, to my knowledge, been found in England. Our present shell 
resembles ¢rigonata in some respects, but it is, I think, distinct. 
There are some specimens in Mr. Edwards’s collection, to which he has given the MS. 
names of Cr. @qualis (fig. 4) and Cr. tumescens (fig. 5), which so closely resemble Cr. 
Bronnii that I have considered them only as varieties. 
M. Deshayes describes his shell as “ marginibus tenui-crenulatis.” Our specimens 
have the margins smooth, as have all our triangular Eocene species. 
3. CRASSATELLA CORBULOIDES, Hdwards MS. Pl. XXIV, fig. 3. 
Spec. Char. Cr. Testé minutd, ovato-trigonuld, inequilaterali, convexiusculd ; con- 
centrice sulcatd, sulcis distantibus ; umbonibus elevatis, acutis, prominentibus ; pedi-regione 
minore et breviore; superné depressd ; siphoni-regione majore, margine convexd ; lunuld 
parvd, depressd, levigatd ; marginibus integris. 
Shell small, ovately triangular, inequilateral, slightly convex, covered with ridges or 
periodical thickenings of growth, rather distant; beaks prominent, and sharp; pedal 
region small, rounded, and somewhat depressed; the other side larger, and convex ; 
lunule small, smooth, and rather deep; margins smooth. 
Diameter, ths of an inch. 
Locality. Stubbington (Zdwards). 
One specimen is in Mr. Edwards’s cabinet with the above name, which I have here 
adopted, as it appears to differ from Cr. Bronnii in being more elevated, and the ridges 
with which it is covered are fewer and more distant. The nearest approach to this shell 
that I know is a recent Mediterranean species figured and described by H. Adams under 
the name Gouldia modesta ; but that has a denticulated margin, and is otherwise distinct. 
4. CRASSATELLA compressa, Lamarck. Pl. XXIII, fig. 5 a, 6. 
CRASSATELLA compressa, Lam. (non Sowerby). An. du Mus., vol. vi, p. 410, No. 4, 
and vol. ix, pl. xx, fig. 5 a, 6, 1806. 
—_— — Desh. Coq. Foss. des Env. de Par., vol. i, p. 37, pl. iu, 
figs. 8, 9, 1824. 
— — Id. An. sans Vert. du Bass. de Par., vol. i, p. 744, pl. xx, 
figs. 9—11, 1860. 
Spec. Char. C. Testa transversd, subtriangulari, compressa, inequilaterali ; tenuiter sul- 
catoplicatd ; pedi-regione obtuse truncatd, ano subsinuoso ; umbonibus minimis, acutis, non- 
