TRENTON LIMESTONE. 97 
134. 8. LINGULA ELONGATA (n. sp.). 
Pu. XXX. Fig. 5. 
Oblong oval, gradually narrowing towards the beak ; sides nearly straight ; shell much 
elevated along the centre, which continues to the beak, and is slightly depressed in front ; 
a narrow depressed line extends along the length of the shell, from the beak, more than 
half way to the base ; surface marked by fine concentric striz, without visible longitudinal 
ones. 
Length of the shell, 1}; width, ;% of an inch. 
I have seen but a single specimen of this shell, but its great elongation, and entire 
freedom from radiating striae, either upon the outer surface or where exfoliated, seem to 
me sufficient marks of distinction. Our shell corresponds in many respects with Lingula 
parallela of Puiturps ( Geol. Yorkshire, Vol. u1., pl. 11, fig. 17-19), as described by 
Porttock ( Geol. Report, pag. 444, pl. 32, figs. 6,8 & 9), but his specimens are much 
smaller ; the original shell, moreover, occurs in a much higher position, which alone would 
be a fair presumption against it being identical with the one of the Trenton limestone. 
Position and locality. In the compact dark limestone in the central part of the rock. 
Lewis county. (Cabinet of Mr. VaNUXxEM.) 
135. 9. LINGULA CURTA. 
PL. XXX. Figs. 6 a, 0. 
Lingula curta. Conran, Jour. Acad. Nat. Science, Vol. viii. pag. 266, pl. 15, fig. 12. 
Obtusely ovate, flat or depressed convex ; beak small, often scarcely prominent ; surface 
marked by concentric elevated lines or wrinkles ; apex obtuse ; base broadly rounded. 
The length and breadth of this shell are nearly equal, and the beak often scarcely projects 
beyond the outline of the shell. In the Utica slate, it is quite flat from compression, ey 
in the limestone it 1s depressed convex. 
Fig. 6 a, is from the Utica slate, the same specimen figured by Mr. Conran. 
Fig. 6 8, is from the Trenton limestone. 
When the shell is exfoliated, fine radiating striz are visible. 
Position and locality. Middleville and East-Canada creek, in the compact dark limestone, 
nearly in the central part of the rock. It occurs also in a higher position, and in the Utica 
slate ; also at Carlisle ( Pa.), in Utica slate. 
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