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. trigonata ; this latter, although so 

 abundant there, has not, to my knowledge, been found in England. Our present shell 

 resembles trigonata 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. cequalis (fig. 4) and Cr. fumescens (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. Cr.^ssatella corbuloides, Edwards MS. PI. XXIV, fig, 3. 



Spec. Char. Cr. Testa minutd, ovato-trigonuld, inaquilaterali, convexiusculd ; con- 

 centrice sulcata, sulcis distantibus ; iimbonibvs elevatis, acutis, prominentibus ; pedi-regione 

 minore et breviore ; superne depressd ; siphoni-regione majore, margine convexd ; lunula 

 parvd, depressd, Icevigatd ; 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, f ths of an inch. 



Locality. Stubbington {Edicards). 



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 imder 

 the name Gouldia modesta ; but that has a denticulated margin, and is otherwise distinct. 



4. Crassatella compressa, Lamarck. PL XXIII, fig. 5 a, b. 



Crassatella compressa, Lam. (non Sowerbj/). An. du Mus., vol. vi, p. 410, No. 4, 



and vol. ix, pi. xx, fig. 5 a, b, 1806. 



— — Desk. Coq. Foss. des Env. de Par., vol. i, p. 37, pi. iii, 



figs. 8, 9, 1824. 



— — Id. An. sans Vert, du Bass, de Par., vol. i, p. 744, pi. xx, 



figs. 9—11, 1860. 



Spec. Char. C. Testa transversa, subtriangulari, compressa, incequilaterali ; tenuiter sul- 

 catoplicatd ; pedi-regione obtuse truncatd,ano subsinuoso ; umbonibus minimis, acutis, non- 



