316 
PALAEONTOLOGY OF NEW YORK. 
In nearly all the well-preserved specimens of this species the beaks have 
been eroded during life, as shown in figures on plate xciii. 
Formation and localities. In the shales of the Hamilton group, at Pratt’s falls 
and Delphi, Onondaga county ; in Schoharie, Otsego and Madison counties, 
and on the shores of Seneca lake. 
Nucula lirata. 
PLATE XLV, FIGS. 5, 11, 15, 17-22, 24, 25; AND PLATE XCIII, FIG. 5. 
Nuculites lirata, Conrad. Jour. Acad. Nat. Sci. Phila., vol. viii, p. 250, pi. 15, fig-. 7. 1842. 
Nucula lineata? (Phillips), Hall. Geol. Surv. N. Y., Rep Fourth Dist., p. 197, No. 7S, fig-. 5, p. 196. 
1843. 
Nucula lirata (Conrad), Hall. Prelim. Notice Lamellibranchiata, 2, p. 3. 1870. 
“ “ “ “ Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 45, figs. 17-27. 1883. 
Not Nucula lineata (Phillips). Palieozoic Fossils, p. 39, pi. IS, fig. 64. 1841. 
Shell of medium size, ovate-triangular; length from one-third to one-fourth 
greater than the height; basal margin regularly curving, more abruptly 
rounded at the posterior extremity; cardinal margin slightly arcuate, grad¬ 
ually sloping toward the posterior. Anterior end short, sub-truncate, usually 
abruptly rounded. 
Yalves very gibbous, ventricose in the umbonal region. 
Beaks, at the anterior third or fourth of the length of the shell, distant, 
elevated, rising considerably above the hinge-line. Umbo very prominent. 
Umbonal slope elevated and rounded, merging into the general convexity 
before reaching the posterior end. 
Test thick, marked by regular, strong, sub-angular concentric undulations, 
which are crossed by extremely fine radiating striae. In older shells the 
margins are marked by fine, concentric striae, the strong undulations having 
become obsolete. 
The characters of the interior are strongly marked, as shown in figs. 24, 
25, plate xlv. 
A specimen preserving both valves in contact has a length of 21 mm., 
height 14.5 mm., and depth of both valves 12 mm. Three separate valves 
measure respectively 22, 20 and 18 mm. in length, and 17, 15.5 and 12 mm. 
in height. 
