314 Lamarck’s Genera of Shells. 
The species are subdivided into, (1) Shells, with the internal 
margin of the valves crenate, or indented, and (a) having 
lamellar strie—13 species; or (b) without lamellar strice— 
14 species. (2) Shells with the internal margin of the valves 
entire—61 species. 
Type. Venus puerpera*. (Idem. Linn.) 
Shell rotundo-cordate, gibbous, subglobular, whitish or fer- 
ruginous; longitudinal strize close together; the transverse, 
membranaceous, and somewhat distant; anus cordate; corselet 
concealed by the lips on the upper part. Indian Ocean. In 
all 88 recent species, and 6 fossil. Pl. vi. Fig. 57. 
4. Venericardiaf. 
Shell equivalve, inequilateral, suborbicular; generally with 
radiating, longitudinal ribs. Two oblique cardinal teeth, simi- 
larly inclined. 
The venericardie seem to connect the conche with the 
cardiacea ; their radiating ribs give them perfectly the appear- 
ance of cardia, and they are allied to the conch by their hinge, 
which would resemble that of the veneres, if it had a third di- 
verging tooth on each valve. They appear, however, to differ 
from the carditee, merely by wanting the lunular tooth, their 
two oblique teeth representing the lateral tooth of the cardite, 
which is always channelled. Moreover, the lunula of these 
shells is always hollow, like those of the cardite, and more or 
less apparent. They are chiefly fossil. 
Type. Venericardia planicostat. 
Shell obliquely cordate, very thick ; ribs flat, entire, posterior 
and anterior obliquely furrowed. Fossil. France, England, 
and Italy, 11Species. Pl.vi. Fig. 58. 
6th Family. 
CarpiacEa, (5 genera.) 
Cardinal teeth irregular, either in form or situation, and 
generally accompanied by one or two lateral teeth. 
* Child-bearing. + Venus and Cardium, as allied to both. 
+ Flat-ribbed. Lamarck’s third species, the V. imbricata, is the Venus 
imbricata of Gmelin. 
