LAMELLIBRANCHIA TA. 
435 
Lunulicabdium Mabcellense. 
PLATE LXXI, FIGS. 15, 16. 
Cypricardites Marcellensis, Vanuxem. Geol. Surv. N. Y., Rep. Third Dist., p. 147, t. 35, fig-. 4. 1842. 
Lunulicardium Marcellense, “ Hall. Prelim. Notice Lamellibranchiata, 2, p. 97. 1870. 
“ “ “ “ Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 71 
figs. 15, 16. 1883. 
Shell of medium size, somewhat obovate, truncate behind; length a little 
greater than the height. Anterior and basal margins regularly curved. Pos¬ 
terior slope obliquely truncate. 
Valves moderately convex below, becoming gibbous in the upper portion. 
Beaks anterior to the middle of the length, erect. 
Test of moderate thickness. Surface marked by fine, closely arranged 
concentric striae. In exfoliated specimens there are indications of radii 
which are often more distinctly marked along the margin of the valve. 
Three specimens measure respectively 30, 35 and 36 mm. in length, and 
32, 33 and 33 mm. in height. 
This form differs somewhat from the figure given by Mr. Vanuxem, and a 
specimen corresponding, in form, to his figure, shows a few distinct plications 
upon the upper anterior margin of the shell. The material in hand is very 
unsatisfactory, and better collections may lead to a separation into two distinct 
species. 
Formation and localities. In the Marcellus shale of Cherry Valley, Sharon 
Springs and Schoharie, N. Y. 
Lunulicabdium bude. 
PLATE LXXI, FIG. 17. 
Lunulicardmm rude. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 71, fig-. 17. 1883. 
Shell of medium size, obovate, obliquely truncate on one side; length and 
height nearly equal. Anterior and basal margins regularly curving. Post- 
cardinal slope obliquely truncate; margin thickened and deflected. 
