418 MOLLUSCA. CARDITAD.^. Cardita. 



6. C. similis. — Rhomboidal, gibbose, transversely costated ; anterior part 

 separated by a projecting serrated keel, lunette heart-shaped, nearly flat : 

 beaks involute. — Soiver. Min. Conch, t. ccxxxii. f. 3. — Inferior Oolite. 



Gen. VENERICARDIA— Shell inequilateral, longitudinally 

 ribbed ; hinge-teeth two, oblique. 



1. V. planicosta — Subcordate, very thick, smooth, ribs broad and flat, about 

 20, expanding into each other towards the margin ; a fevf longitudinal teeth 

 within the posterior edge. — Sower. Min. Conch, t. 1. — London Clay. 



2. V. senilis Obliquely cordate, thick, with large, convex, subimbricated, 



naked ribs; lunette obsolete — Park. Org. Rem. iii. 191. t. xiii. f. 15, 17- 

 Sower. Min. Conch, t. cclviii — In Crag. 



3. v. carinaia Transversely oblong, with 20, nearly smooth, carinated 



ribs ; lunette obsolete.— iSower. Min. Conch, t. cclix — In London Clay. 



4. V. deltoidea Deltoid, with rounded angles; ribs 15, keel-formed ; hinge 



callous, beaks prominent; lunette small — Sower. Min. Conch, t. cclix. f. 1. 

 — In London Clay. 



5. V. globosa Globose; costje 1 G to 20, carinated ; carinae tubertailated» 



tubercles compressed — (Chama sulcata, Brander, f. 100.) Sower. Min. Conch, 

 t. cclxxxix. upper and middle figures. — London Clay. 



6. V. oblonga — Transversely oblong, unequal sided, subquadrangular, gib- 

 bose, with 13 knotted costte ; length about two-thirds the width ; costa^ strong, 

 obtuse, irregularly knotted, margin strongly toothed — Sower. Min. Conch, 

 t. cclix. three lower figures. — London Clay. 



7. V. chamaformis. — Convex, orbicular, with rather produced beaks ; ribs 

 rugged, distant, about 14 ; hinge large — Sower. Min. Conch, t. ccccxc. f. 1. — 

 In Crag. 



8. V. orbicularis Orbicular, rather convex, concentrically striated ; ribs 



about 16, not close, crenated ; hinge small — A'ower. Min. Conch, t. ccccxc. 

 f. 2 In Crag. 



9. V. scalaris — Orbicular subtriangular, depressed ; longitudinal sulci about 

 20, linear, concentrically striated ; hinge-teeth long and thin. — Sower. Min. 

 Conch, t. ccccxc. f. 3 — In Crag. 



Gen. CRASSATELLA.— Shell inequilateral; hinge with 

 two strong teeth in one valve, receiving one tooth from the 

 other ; ligament inserted in a pit at the side of the teeth. 



1. C. sulcata. — Ovato-elongated, transversely sulcated ; anterior side pro- 

 duced, obliquely truncated, defined by a ridge ; edge-toothed within. — (TeUina 

 sulcata, Brander, f. 80.) — Sower. Min. Conch, t. cccxlv. f. 1. — In London 

 Clay. 



2. C. jD?icato.— Oblong, ovate, concentrically and minutely plicated ; plicae 

 reflectCi! ; anterior side defined by an obtuse ridge, obscurely truncated ; 

 margin toothed within. — Sowert Min. Conch, t. cccxlv. f. 2. — In Lmidon 

 Clay. 



