408 MOLLUSCA SUB-KINGDOM vi 



Lucina, Brug. (Figs. 741-744). Rounded, convex, or lenticular, usually with a 



FIG. 741. 

 Lucina (Miltha) gigantea, Desh. Eocene (Calcaire Grossier) ; Grignon, near Paris. 2/ 3 . 



lunule ; with delicate, concentric, or more rarely radial sculpture ; dentition usually 



FIG. 742. 



Liunna pulchra, Zitt. and Goub. Coral-Rag ; 

 Glos, Calvados. 2/j. 



Lucina (Prolucina) prisca, His. Silurian ; Gottland. 

 Internal cast (after Roeiner). 



normal, the laterals developed. Represented by upwards of 300 fossil and 100 recent 

 species. ? Silurian, Trias to Recent. 



Sub-genera: Lucina s.s., Lam. 1799 (Loripes, auct.) Shell smooth. Adult with the 



teeth and posterior radial plication of the valves obsolete. 

 Tertiary and Recent. 



Prolucina, Ball (Fig. 743). Compressed, arcuate, 

 almost rostrate ; the anterior side larger. Silurian. 



Myrtea, Turton (Fig. 744). Rounded, sub -equi- 

 lateral ; teeth and posterior fold present. Tertiary and 

 Recent. 



Codakia, Scopoli. Compressed, reticulately sculp- 

 tured. Tertiary and Recent. 



Miltha, Adams. (Fig. 741). Compressed, nearly 

 smooth ; laterals absent, cardinals long, feeble (3. 2). 

 Tertiary and Recent. 



Divaricella, Martens. Rounded, inflated, valves ornamented with angular divergent 

 grooving. Tertiary and Recent. 



Lucina {Myrtea) columbella, Lam. Mio- 

 cene ; Steinabrann, near Vienna. 



