35 



S. NOVACULA. Mont. p. 47. Turt. B. p. 80. 

 P.p. 459. A single strong, curved, blunt tooth in each 

 valve; shell destitute of the terminal stricture. . 

 Nearly resembling the following but differing by the 

 number of its teeth and the absence of the lateral ones. 



S. SILIQUA. Zm. 1113. D.p. 58. Lam. 4. Ch. 

 29. Don. t. 46. Pen. 4. p. 83. t. 45. /. 20. 

 Mont. p. 46. Turt. B. p. 80. F. 459. Straight, 

 with an olive brown cuticle which is darkest posteriorly ; 

 a single tooth and a remote lateral lamina in one valve, 

 in the other, are two besides a lateral inclined tooth 

 corresponding with the opposite lamina. 1...7. 

 Common. 



S. ENSIS. Lin. 1114. D.p. 59. Lam. 5.Ch.f. 

 29, 30. Dow. t. 50. Pen. .p. 83. Mont. p. 48 

 Turt. B.p. 82. F. p. 459. Linear, slightly curved, 

 the cuticle olive brown, both the ends somewhat 

 rounded ; two teeth in one valve, one in the other, one 

 of the lateral teeth grooved ; hinge not terminal ; pos- 

 teriorly rounded. I...6. Common. 



* * Hinge not terminal ; posteriorly rounded. 



S. PELLUCIDUS. Pen. 4. t. 46. /. 22, Mont. p. 49. 

 Turt. B.p. 83. D.p.60, />.549. S. PYGMJEUS, 



