418 MOLLUSCA. CARDITADiE. Carhtta. 



5. C. similis. — Ithomboidal, gibbose, transversely costated ; anterior part 

 separated by a projecting serrated keel, lunette heart-shaped, nearly Hat ; 

 beaks involute — Sower. Min. Conch, t. ccxxxii. £ 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 few 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. Item. iii. 191. t. xiii. 1*. 15, 17. 

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



3. V. carinala Transversely oblong, with 20, nearly smooth, carinated 



ribs ; lunette obsolete. — Sower. 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; costae 1G to 20, carinated ; carinte tuberculated, 

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

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



C. V. ohlonga. — Transversely oblong, unequal sided, subquadrangular, gib- 

 bose, with 13 knotted costse; length about two-thirds the width; costae strong, 

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

 t. cclix. three lower figures — London Clay. 



7. V. chammformis 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 — Sozver. Min. Conch, t. ccccxc. 

 f. 2 — In Crag. 



9. V. scaluris — 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. — (Tellina 

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

 Clay. 



2. C. plicata. — Oblong, ovate, concentrically and minutely plicated ; plica? 

 reflected ; anterior side defined by an obtuse ridge, obscurely truncated ; 

 margin toothed within. — Sower. Min. Conch, t. cccxlv. f. 2. — In London 



Clay. 



