36 PALEONTOLOGY OF NEW JERSEY. 
and nearly all the loealities of Miocene fossils throughout that part of the 
State of New Jersey. They appear in the gray marls and in the limestone, 
and also in the brown clay. 
HETEROMYARIA. 
Family AVICULIDA#=Pteride. 
Genus PERNA Bruguieére. 
+ 
PERNA TORTA. 
Plate v, figs. 12 and 13. 
Perna torta Say: Am. Jour. Sci. and Arts., Ist series, vol. 2, p. 58. 
Perna mavillata Conrad: Miocene Foss., p. 51, pl. 27; (non Lam.) 
Perna Conradi D’Orb.: Prodrome, vol. 3, p. 127. 
Tsognomon torta (Say sp.) Conrad: Cat. Miocene Foss., Phil. Acad. Nat. Sci., 1862, p. 
579. 
Melina torta (Say sp.) Meek: Check List Miocene Foss., p. 6. 
Shell very large, attaining a length of 7 inches, and a width of at least 
34 inches. Form obliquely ovate, pointed at the beak, which is directed 
forward Anterior and posterior margins subparallel and the lower margin 
rather sharply r¢ sunded. Hinge line very oblique to the axis in the young 
stages of growth, but less distinctly so in the larger individuals, and its 
margin somewhat arched. General surface moderately convex. Liga- 
mental area broad and as long as the shell, extending from the beak to the 
posterior margin of the valves; vertically marked by ligamental grooves, 
which extend the entire width and number from fifteen to near twenty 
according to the size and age of the shell, and equal in size on the two valves, 
so far as can be seen in the best preserved individuals. Substance of the 
shell, very thick, strongly lamellar, and highly nacreous. Muscular pits 
deeply marked. 
I have never seen a specimen of this species which was anything like 
entire, and the New Jersey specimens are always very imperfect. A single 
partial cast, measurmg about 34 inches in length, but almost entirely coated 
with a thin layer of shell, gives nearly the whole outline, and shows it to 
correspond very closely to the form given by Mr. Conrad for a Maryland 
specimen. It is a little more sinuate at the byssal opening only. ‘The larg- 
