BIVALVIA. 145 
(Tab. XXII, fig. 2, from Brook), which appear to me to be a variety of this species. 
These are not quite so much inflated; they resemble much the figure and description 
of C. Aizyensis, Desh., differing slightly in the ornamentation. Our shells are not quite 
orbicular, but have a greater diameter from the umbo to the ventral margin than in the 
opposite direction. 
6. Carpita Davinsont, Deshayes. Tab. XXII, fig. 17, a, 6. 
Carpita Davripsont, Desh. An. sans Vert. du Bas. de Par., t. i, p. 764, pl. 60, figs. 
10—12, 1860. 
Spec. Char. OC. Testé orbiculato-subtrigonuld, depressiusculd, crassa, inequilaterali, 
radiatim costatd, costis 17—19 angustis, distantibus, obsolete tricarinatis ;  crenato- 
squamosis, interstilis latis, irregulariter striatis ; umbonibus acutis ; lunuld minima, 
levigalé ; cardine crassiusculo. 
Shell roundedly trigonular, somewhat depressed, thick, inequilateral ; costated ribs 
17—19, distant, narrow, and obsoletely triangular ; outer keel covered with rather distant 
squamose tubercles ; interstices broad, and covered with concentric striz or irregular lines 
of growth ; beaks sharp, lunule small and smooth. 
Diameter, 3ths of an inch. 
Locality. Barton. 
France: Ver. Ermonville (Des/.). 
This species is by no means rare in England at the above locality ; it much resembles 
C. sulcata, but it is not so tumid, the coste are fewer, more distant, the tubercles on the 
ribs are not so numerous, the ribs are more angulated and not so rounded, and there is 
generally a distinct line on each side of the keel. ‘The elongated tooth is nearly parallel 
with the ligamental fulcrum extending laterally beyond it. The valves are not so 
frequently found united as are those of sa/eata. 
7. Carpira peLtopEA, J. Sowerby. ‘Tab. XXII, fig. 7, a, 6. 
VENERICARDIA DELTOIDEA, J. Sow. Min. Conch., tab. 259, fig. 1, 1821. 
— LatisuLcata, Wyst. Coq. foss. de Belg., p. 209, pl. xv, fig. 5, a, 6, 
1843, fide Von Konen. 
Spec. Char. C. Testa obliqui, subtrigond vel deltoided, crassa, convexiusculd, inequi- 
laterali, radiatim costatd, costis 15—18 acutis, elevatis, distantibus ; lunuld magna, 
levigatd, depressd ; umbonibus elevatis, incurvis, obliquis ; cardine crassissimo. 
Shell oblique, subtrigonular or deltoidal, thick and strong, slightly convex, inequi- 
20 
