TRIBE CONCHACEA. 109 



C. Ltjnut.aris.^ Lean. 74. — Del. t. 9. J". 6. Sub-orbicular 

 heart-shaped, longer than broad, transversely grooved, livid, rayed 

 towards the margin : the lunule with a white triangular spot at its 

 base: inside white. 1^. — America? 



C. Cygnus. Lam. 77. Heart-shaped, tumid, uniform white 

 within and without, with raised transverse striae which become 

 smaller towards the margin ; the beaks incUning towards the 

 heart-shaped lunule. li. — Mediterraneayi. 



C. Dentaria. Lam. 78. Ti-iangular broadly, transverse, pale 

 fulvous with white rays, and the anterior side with a reddish-brown 

 spot more apparent in the interior. 2g. — Rio Janeiro. 



C. Effossa. Nobis, in Z. P. 1842„ Oval, sub-cordiform, sub- 

 equilateral, thick, glossy, convex, with strong rather distant trans- 

 verse grooves, the intervening spaces flattened, pale livid variegated 

 by darker zigzag veins ; lunule impressed and lanceolate : lozenge 

 deeply excavated, the sides smooth, white with wavy transverse ches- 

 nut bands : inner disc stained with purple ; inner margin distinctly 

 crenated. ^ . . 1^. 



C. Excavata. Nobis in Z. P. 1842. Rounded ovate, sub- 

 equilateral, posteriorly expanded, anteriorly narrowed by the much 

 arcuated ventral margin sweeping obliquely upward to meet the 

 posterior edge ; thick, smooth, glossy, pale fulvous, more or less 

 distinctly marbled with livid angular markings : lunule lanceolate : 

 lozenge very deeply excavated, the sides flattened, white with a few 

 livid veins : inner disc with a pale crimson stain, inner margin 

 finely crenulated. 1 . . 1^. 



C. SoLANDRi. Gray in Ann. Phil. — C. Hyans. W. S. t. 2. 

 y. 1 1 . Elliptical-sub-cordiform, thick, very convex, sub-equilateral, 

 smooth, polished, white with angular clouded livid purple markings, 

 especially near the umbones : lunule and lozenge lanceolate, the 

 former indistinct, the latter excavated: margin crenulated. l^ . . \^. 

 — China. — Alan with the two 2)recedi7ig to JDonax Scripta. 



VENUS. 



Equivalve, inequilateral, transverse, or sub-orbicular ; hinge with 

 three teeth in both valves, all approximate, the lateral ones 

 divergent at their summits ; ligament external, concealing the 

 lozenge. 



* Inner margin crenulated or toothed. 



Section A. — With lamellar strife. 



Vc PuERPERA. Lin. Mantissa, p. 545. — Lam. 1. (excluding 

 var.2.)—D.p. 188.— CA./. 388, 9.— £•. t. 278./. I.— Peeve. 



1 C, Flexuosa. La7n. 72. — Macrodon. 73, — Squamosa, 75, 

 and Cabdilla, 76, belong to Venus. 



