512 
PALAEONTOLOGY OF NEW YORK. 
but the characters of the hinge are very distinctive, and there is no defined 
umbonal ridge extending to the post-inferior extremity. 
Formation and locality. In the shales of the Hamilton group, in Hardy 
county, Ya. 
CLINOPISTHA, Meek and Worthen. 1870. 
Clinopistha subnasuta. 
PLATE LI, FIGS. 32, 33 ; and PLATE XCV, FIG. 31. 
Tellinomya [Dystactella] subnasuta , Hall and Whitfield. Twenty-fourth Ann. Rep. N. Y. State Mus. 
Nat. Hist., p. 191. 1872. 
Dystactella subnasuta (Hall and Whitfield), S. A. Miller. Cat. Am. Pal. Foss., p. 190. 1877. 
“ “ “ “ Hall. Pal. N. Y., vol. v, pt. 1. Plates'and Explanations: 
PI. 51, fig-s. 32, 33. 1883. 
Shell small, narrowly sub-elliptical, nearly straight on the basal side; length 
about twice the height. Basal margin nearly straight, curving abruptly to 
the anterior and more gently to the posterior end. Posterior extremity 
rounded. Cardinal line gently arcuate. Anterior end short, sub-nasute, 
declining from the beaks and narrowly rounded below. The place of the 
lunule is occupied by a fold or callosity which is distinctly limited by the 
margins of the valve. 
Valves moderately convex below and posteriorly, gibbous in the umbonal 
region. 
Beaks at about the anterior third, small, closely appressed. Umbonla 
slope convex, not defined. 
Test thin. Surface marked by somewhat regular, fine, thread-like strife 
of growth, which in the perfect condition of the shell may have been lamel- 
lose, and are fasciculate on some individuals. 
The hinge shows some appearance of having been crenulated, but the con¬ 
dition of the specimens is such as not to admit of positive determination. 
Muscular impressions distinct. Pallial line entire, marked in the cast by a 
series of radiating pustules. 
Three specimens measure respectively 21, 26 and 27 mm. in length, and 
12, 13 and 13 mm. in height. 
