37 



AVICULA. 



GENERIC CHARACTER: Shell unequal valved, brittle, 

 rather smooth ; base transverse, straight ; the extremities 

 produced, the anterior like a tail ; a sinus in the left valve; 

 hinge linear, one toothed ; a cardinal tooth in each valve 

 under the beaks. Facet of the ligament marginal, narrow, 

 channelled, not traversed by the byssus. 



AVICULA HIRUNDO. Flem. Brit. An., p. 405. A 

 specimen of this rare shell, taken in Plymouth sound, is 

 in the possession of Dr. Edward Moore. 



PECT1NIDA. 

 The ligament internal, or partly so. Shell in general 

 regular, compact, not foliated. 



LIMA. 



GENERIC CHARACTER: The shell longitudinal, the 

 valves nearly equal, eared, gaping slightly on one side 

 between them; beaks distant, their internal facet inclined 

 outwards ; hinge without teeth. The cardinal pit partly 

 external, receiving the ligament. 



L. FRAGIL1S. Flem. Brit. An., p. 388. It approaches to, 

 but does not strictly correspond with the figure and des- 

 cription of Mr. Forbes, in the Mag. Nat. Hist., vol. 8, 

 p. 594, fig, 65. Length one inch and three-tenths, breadth 

 nine-tenths of an inch. The valves equal, oblique, inflated, 

 thin but not brittle, scarcely marked with lines of growth, 

 and with obscure, not pectinated longitudinal striae ; gaping 

 at both sides, touching only at the ears, and extremity of 

 the margin. Colour pale yellow. I obtained a single 

 specimen from the trawl at Falmouth. 



PECTEN. 



GENERIC CHARACTER: The shell free, regular, the 

 valves unequal, with ears; the lower margin trans- 

 verse, straight; beaks contiguous ; hinge without teeth; 

 a cardinal triangular pit, wholly internal receiving the 

 ligament. 



* P. MAXIMUS, Ostrea M. Turt. Lin. Pecten M. 



Pen. Brit. Zo., vol. 4, pi. 59, a view of the under valve; 



Mont. Test. Brit., vol. 1. p. 143. Flem. Brit. An., p. 383. 



Scallop. Common in moderately deep water. 

 P. JACOB^EUS. Ostrea J. Turt. Lin. Pecten J. Pen. 



Brit. Zo., vol. 4, pi. 60, fig. 62. Mont. Test. Brit., vol. 1, 



p. 144. Flem. Brit. An., p. 388. Scarcely common. 

 •P. OPERCULARS. Ostrea O. Turt. Lin. Pecten 



Subrufus. Pen. Brit. Zo., vol. 4, pi. 60, fig. 63. P. 



Opercularis- Mont. Test. Brit., vol. 1, p. 145. Flem. 



Brit. Au., p. 383. Taken abundantly in trawls, and 



carried to market. 



