NO. 1312. SYNOPSIS OF THE VENERIDjE— BALL. 351 



Subgenus Circe Schumacher. Type, Venus scrtpta T.innivus. 



Shell compressed, with only concentvic sculpture, with smooth com- 

 pressed beaks, narrow lunule and escutcheon; pallial line simple, jimcr 

 maro-ins smooth; posterior right cardinal grooved: ligament d(!epW 

 sunken, but not entii'ely immersed. 



Section Puninilhin Dall, 1902. Type, Circe cornujdtii (Dillwvn) 

 Deshayes. 



Shell with the umbonal region flattened and coarsely divaricately 

 ribbed, the rest of the surface concentrically sculptured; disk (except 

 the umbones) convex; pallial line slightly flexuous, inner margins 

 finel}' crenulate; lunvile and escutcheon narrow, flat, the ligament 

 depressed; cardinals entire or faintl}" grooved. 



Section (Jircenita Jousseaume, 1888. Type, C. (irahiva Lamarck. 



Valves convex; surface feebly concentrically sculptured, the beaks 

 not compressed; posterior slope without specialized sculpture; lunule 

 distinct, narrow, escutcheon hardlv deflned; ligament hardly depressed; 

 pallial line with a minute sinus, the inner margins of the valves entire. 



Genus LIOCONCHA Morch, 18§3. 



Type, Venus eastreiisis Linnasus. 



Shell solid, porcellanous, suborbicular, smooth or concentrically 

 sculi)tured, vividly colored; lunule sharplv circumscribed, impressed, 

 but no defined escutcheon; ligament almost immersed, pallial line 

 slightly flexuous, inner margins smooth, anterior left and posterior 

 right dorsal margins grooved to receive the beveled edge of the oppo- 

 site valve; anterior lateral large and strong; three smooth, entire 

 cardinals in each valve. 



Tropical seas of the Old World. 



Genus MACROCALLISTA Meek, 1876. 



Type, Ve7iu>< nimhosa Solander. 



Shell ovate, microscopicallv radially lineated, with low concentric 

 waves, or smooth, with vivid coloration and vernicose periostiacum; a 

 defined lunule, l)ut unequally divided between the valves; no defined 

 escutcheon; internal margins smooth, pallial sinus free, ample. pointed 

 in front and horizontally directed; cardinals three in each valve, 

 smooth and entire, except a bifid right posterior tooth. 



Section ^Lio'ocalUsta s. s. 



Shell much elongated, the pallial sinus short, the posterioi- cardi- 

 nals slender and elongated. 



The type is better known as Cytherea or Callista giganttu (Gmelin) 

 Lamarck. 



Section (Jhkmella Cossman, 1886. Type, Cytherea ovallna Deshayes. 



Shell ovate-trigonal; pallial sinus long; the posterior cardinals 

 short. 



