160 AMERICAN MARINE CONCHOLOGY. 



elevated, remote, lamellar bands, white, with blotches of red or 

 purple, or bluish-gray. 



Length 22.5, height 20 mill. 



North Carolina, southwards. 



2. C. TRAPEZOIDALIS, KUrtZ. 



(Venus.) Cat. Shells, K and S. Car. 1860. 



Shell covered with convex radiating ribs, set with brown spots 

 and scales of growth. A thin brown pile on good specimens. 



Length 12.5 mill. 



North and South Carolina. 



Fossil Species. 



C. ALVEATA ( Venus), Conrad. 

 C. IN^EQUALIS ( Venus), Say. 



These species are included in Stimpson's Catalogue of Shells of 

 the Atlantic Coast, but I am confident they have not been found 

 except in a fossilized condition. 



Genus CALLISTA, Poll. 

 Test. Sicil., i. 30. 1791. 



The mantle margins are plicate, with filaments above the base of 

 the respiratory siphon ; siphons united to their ends, crowned 

 with simple cirrhi. 



1. C. GIGANTEA, Chemnitz. Fig. 396. 



Conch. Cab., f. 1661. 



Shell large, ovate, smooth, slightly angulated on the anterior 

 side; posterior depression oblong-ovate, a little impressed on its 

 sides and keeled in the middle. Teeth compressed. Color pale 

 livid with numerous lilac longitudinal broad rays, generally inter- 

 rupted. 



Length 6, height 3.25 inches. 



North Carolina, southwards. 



2. C. MACULATA, Linnaeus. Fig. 397. 



\Venus.) Syst. Nat., edit. xii. 432. 1767. 



Shell oval, rather compressed, posteriorly; obliquely somewhat 

 produced'; fawn white, blotched or waved with violet brown, en- 

 veloped with a shining horny epidermis. 



Georgia to West Indies. 



3. C. SAYANA, Conrad. Fig. 398. 



(Cytlierea.) Am. Journ. Science, xxiii. 345. 1833. 

 C. convexa, Say, of authors. 

 Shell moderately solid, ventricose, subcordate ; beaks elevated, 



