37 
AVICULA. 
GENERIC CHARACTER: Shell unequal valved, brittle, 
r »ther smooth; base transverse, straight; the extremities 
Produced, the anterior like a tail ; a sinus in the left valve; 
binge linear, one toothed ; a cardinal tooth in each valve 
under the beaks. Facet of the ligament marginal, narrow, 
channelled, not traversed by the byssus. 
Avr ICULA HIRUNDO. Flem. Brit. An., p. 405. A 
specimen of this rare shell, taken in Plymouth sound, is 
'U the possession of Dr. Edward Moore. 
PECTINIDA. 
r J'ho ligament internal, or partly so. Shell in general 
»"!ar, compact, not foliated. 
LIMA. 
GENERIC CHARACTER: The shell longitudinal, the 
j'Ulves nearly equal, eared, gaping slightly on one side 
between them; beaks distant, their internal facet inclined 
cutwards ; hinge without teeth. The cardinal pit partly 
» external, receiving the ligament.. 
‘ cRAGILIS. Flem. Brit. An., p. 388. It approaches to, 
but does not strictly correspond with the figure and des- 
Cr iption of Mr. Forbes, in the Mag. Nat. Hist., vol. 8, 
P; 594, fig, 65. LeDglh one inch and three-tenths, breadth 
u i ne- tenths of an inch. The valves equal, oblique, inflated, 
l,, in but not brittle, scarcely marked with lines of growth, 
an d with obscure, not pectinated longitudinal striae ; gaping 
both sides, touching only at the ears, and extremity of 
be margin. Colour pale yellow. I obtained a single 
s Peciinen from the trawl at Falmouth, 
G PECTEN. 
ENERJC CHARACTER: The shell free, regular, the 
a ‘ v ®s unequal, with ears; the lower margin trans- 
erse , straight; beaks contiguous; hinge without teeth; 
?. cardinal triangular pit, wholly internal receiving the 
♦ JSatnenl. 
p AlAXIMUS, Ostrea M. Turt. Lin. Pecten M. 
en. Brit. Zo., vol. 4, pi. 59, a view of the under valve; 
^ut. Test. Brit,, vol. 1. p. 143. Flem. Brit. An., p. 383. 
p Common in moderately deep water, 
j ACOB^EUS. Ostrea J. Turt. Lin. Pecten J. Pen. 
r, C Zo., vol. 4, pi. CO, lig. 62. Mont. Test. Brit., vol. 1, 
« jP" 144. Flem. Brit. An., p. 388. Scarcely common. 
■ OPERCULARIS. Ostrea O. Turt. Lin. P € 
Sub 
Pecten 
„ bfufus. p eD . Brit. Zo., vol. 4, pi. 60, fig. 63. P. 
gpercularis. Mont. Test. Brit., vol. 1, p. 145. Flem. 
car" , An- ’ P* 383 ‘ Taken abundantly in trawls, and 
rie d to market. 
