176 EOCENE MOLLUSCA. 
The lamellz are dwarfish and the rays broad, flat, and regular. ‘I'he specimen figured 
is a lower valve, and had been attached by nearly half the entire surface. The rays 
are much more numerous than upon Ch. sguamosa. The inner lining of this shell is 
without punctures. ‘I'he tooth of the lower or adherent valve is rugose; so also is the 
place of its reception in the opposite valve. 
6. Cuama Sruszyensis, Edwards MS. Pl. XXV, fig. 5. 
Spee.Char. Testd orbiculato-rotundatd, inflata, valvd sinistra majore ; umbonibus obliquis, 
incurvatis ; lamellis transversis distantibus, acutis, interstitiis levigatis ; cardine unidentato 
in valvuld sinistra. 
Shell more or less rounded and inflated; left valve the lower and larger; beaks 
oblique and incurved, covered with smooth and sharp lamelle ; interstices free from 
radiations; one tooth in the left valve. 
Diameter, \ inch. 
Locality. Selsey (Edwards). 
Several specimens of what is here considered as a distinct species are in Mr. Edwards's 
cabinet, all exhibiting the same peculiarly smooth character like the one figured, from 
which it seems to have been entitled to specific isolation. I believe it is so, and have 
adopted the MS. name. It appears to be distinguished from gigas by the smoothness 
of the exterior and the freedom from fimbriated lamellae. It somewhat resembles CA. 
inornata, Desh. (pl. lviii, figs. 20—22), and might possibly be the same if a large series of 
each could be examined and compared; but the French shell seems to be elaborately 
ornamented with undulating fimbriz, and I have preferred keeping it as a distinct species 
for the present. 
7. Cuama turcipua (?), Lamarck. Pl. XXV, fig. 9 a—c. 
Cuama TURGIDULA, Lam. An. sans Vert., 2nd ed., t. vi, p. 585, fide Desh., 1860. 
—  rusticuzta, Desh. Coq. Foss. des Env. de Par., p. 249, pl. xxxviul, figs. 7, 8, 1823. 
—  sussTriata, Id. Tbid., pl. xxxviii, figs. 1—3, 1825. 
Spec. Char. Ch. Testé suborbiculatd, convead, crassa, multilamellata, longitudinaliter 
multistriata ; lamellis numerosis incrassatis, subplicatis; striis flexuosis, approximatis ; 
umbone valve inferioris contorto. 
Shell suborbicular, convex, thick, numerously striated with somewhat close-set fimbriz ; 
umbo of inferior valve incurved. 
Diameter, \ inch. 
Locality. Barton. 
