BIVALVE SHELLS. 119 



tico longiore ; margines tenue crenulati ; ligamentum externum 

 angustum ; impressio pallii sinu postico fere nullo vel brevissimo 

 et triangular! terminata. 



Pectunculus, Lister (1685), Conch, pi. 282, &c. 



Petiver (1711), Gazoph. pi. 75. 



Da Costa (1778), Conch. Brit. p. 191, &c. 

 Venus (spec), Linn. (1758) Syst. Nat. ed. 10; (1767) ed. 12. 

 p. 1128. 



Chemnitz, Schroter, Gmelin, Dillwyn, Lamarck, 4'c. 

 Callista et Callistoderma (spec.), Poli (1795), Test. Sicil. ii. 

 Chione, Megerle (1811), Entw. p. 51 (non Gray, 1838). 



Gray (1847), Proc. Zool. Soc. p. 183. 

 Antigone, Schumacher (1817), Essai d'une Class, p. 154. 

 Ortygia, Brown (1827), Test. Brit. 

 Timoclea, Leach (1819), MS. teste Gray. 



Synopsis Specierum. 

 I. Species lamellosse. 



a. Lamella membranacea, 1-13. "*■ 



b. Lamella breviores, crassiores, 14-20. 



c. Lamella crassissimce, 21-28. 

 II. Species cancellatae. 



a. Trigonce, 29-51. 



b. Ovatce, cordiformes, 52-56, 



III. Species decussatse, 57-72. 



IV. Species transversim striata?, 73-92. 

 V. Species laevigatse, 93-108. 



Species incertce, 109-129. 



I. Species lamellosce. 



a. Lamella membranacea. 



1. Chione lamellata. B.M. 



C. testa ovali, antice angulata, albida; lamellis transversis, di- 

 stantibus, antice appendiculatis, latere superiore striatis. 



Venus lamellata, Lamk. An. s. Vert. ed. 2. vi. 349. no. 28. 

 Reeve, Conch. Syst. pi. 6S. f. 3. 

 Deless. Rec. de Coq. pi. 10. f. 6, a, b. 

 Hanley, Descr. Cat. p. 119. 



