LAMELLIBRANCHIA TA. 
335 
This shell is delicate in texture, smaller, more elongate, and with beaks more 
nearly central than P. constrida. 
Formations and localities. In the shales of the Hamilton group, in Otsego 
county, on the shores of Cayuga, Seneca and Canandaigua lakes; and in the 
lower bed's of the Chemung group, at Ithaca, N. Y. 
Pal^eoneilo maxima. 
PLATE XLVIII, FIGS. 29-38. 
Nuculites maxima, Conrad. Geol. Surv. N. Y., Ann. Rep., p. 50. 1841. 
Tellina? ovata, Hali,. Geol. Surv. N. Y., Rep. Fourth Dist., p. 196, fig'. 6. 1S43. 
PalOBoneilo maxima (Conrad), Hall. Prelim. Notice Lamellibranchiata, 2, p. 9. 1870. 
“ “ “ “ Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 48, tigs. 29- 
38. 1883. 
Shell large, ovate-acute ; length one-half greater than the height; basal margin 
very convex in the middle, curving regularly to the anterior end, and more 
nearly straight behind. Posterior extremity narrow and abruptly rounded, 
or sub-truncate at the termination. Cardinal line declining rapidly on either 
side of the beak. Anterior end somewhat narrowly rounded. 
Valves regularly convex below, becoming gibbous in the middle and above. 
Beaks anterior to the centre, prominent, small, with the apices very 
slightly incurved. Umbonal ridge distinct, sub-angular, extending to the 
upper side of the posterior extremity ; the furrow below is broad, obscure 
and undefined. 
Surface marked by fine concentric strise, which are often very obscure or 
obsolescent. Muscular scars unknown. Hinge-line crenulate, but not prop¬ 
erly represented in figs. 37 and 38 of plate xlviii. 
Three specimens measure respectively 31, 32.5 and 35 mm. in length, and 
17, 19 and 20 mm. in height. 
This species differs from all the preceding in its more gibbous form and 
abruptly contracted posterior end, approached only by some of the elongate 
forms of P. constrida. Its internal characters are obscure. 
Formation and localities. In the shales of the Hamilton group, at Summit and 
Fultonham, Schoharie county, and on the shores of Cayuga lake, N. Y. 
