Lamarck’s Genera of Shells. 303 
Type. Petricola striata *. 
Shell ovate triangular, striated with close-set longitudinal 
furrows; transverse strice fewer; anterior side compressed, 
Mediterranean. 13Species. Pl. v. Fig. 41. 
3. Venerupis Tf. 
Shell transverse, inequilateral, posterior side very short, an- 
terior slightly gaping. Two cardinal teeth on the right valve, 
three on the left, sometimes three on each ; teeth small, approxi- 
mate, parallel, and scarcely or not at all diverging. Ligament 
external. 
The hinge of the venerupes appears analogous to that of the 
yeneres, but they are distinguished from them by the cardinal 
teeth, which are somewhat differently disposed. They are per- 
forating shells, and differ from the petricole, by having three 
cardinal teeth, at least on one valve. 
Type. Venerupis perforans t. (Venus perforans. Montag.) 
Shell ovate, rhomboidal, transversely striated ; anterior side 
longest, lamellar, subtruncated. English Coast. 7 Species. 
Pl. vy. Fig. 42. 
4th Family. 
Nympnacea. (10 genera.) 
Two cardinal teeth, at most, on the same valve. Shell often 
slightly gaping at the lateral extremities. Ligament external. 
Nymphe § generally projecting externally. 
This family is subdivided, into N. solenaria, and N. tellinaria. 
The first subdivision contains three genera, the second seven. 
Of the nymphacea, some were referred to the solenes, and 
some to the tellinee, to neither of which, any of them, properly 
belong. The animal of these shells has a small, often com- 
pressed foot, neither similar to, nor disposed like, that of the 
* Striated—Lamarck’s fifth species. His typeis P. lamellosa. 
+ From Venus, and rupes, arock. The Venus of the rocks. 
+ Perforating. as 
§ Nymphe—Impressions, remains, or indications of the situation of the 
nerve, or ligament, particularly visible in some of the veneres. They are 
situated under the beaks, or summits, before or in the centre of the corselet, 
i. e., the part which contains the ligament.—De Montfort, vol. J, Ixxii, 
