298 PALEONTOLOGY OF NEW-YoRK. 
355. 15. MODIOLOPSIS ANODONTOIDES. 
Pu. LXXXII. Figs. 3 a, b, ¢. 
Cypricardites anodontoides. CoNRAD. 
_ sinuata. Emmons, Geol. Report, 1842, pag. 399, fig. 3. 
General figure subelliptical, very convex; beak elevated, with a strong angular ridge 
extending to the posterior basal margin ; cardinal margin nearly straight; posterior extremity 
obliquely truncated; base contracted just below or a little posterior to the beak; surface 
marked by strong concentric strie ; length a little more than twice the height. 
This species is readily recognized by its great umbonical elevation, and the prominent 
oblique carina extending from the beak to the posterior basal extremity. Its form and 
proportions are quite different from either of the preceding, showing that it is a distinct 
species. It is exceedingly rare, but few individuals being known, and these, with one 
exception, are confined to the arenaceous portions of the group. 
I have united the Cypricardites sinuata of Emmons, id. cit., with this species, regarding 
them as identical, the difference in form being due to pressure, and the occurrence of the 
former in soft shale, which has preserved the external markings more perfectly than in the 
specimens from sandstone. 
Fig. 3 a. A specimen in sandstone, preserving the original form of the shell. This specimen is the 
original of C. anodontoides. 
Fig. 3 b. A specimen in soft shale, more compressed than the preceding, and consequently rounded at 
the posterior extremity. This one is the original of C. sinuata. 
Fig. 3c. A specimen in shale, where both valves are still adhering. This is associated with the last, 
having the same surface markings, but is less compressed, and in form like fig. 3 a. 
Position and locality. This species occurs in the lower shaly part of the group, in Rod- 
man, and in the upper arenaceous part, at Loraine, Jefferson county. (State Collection.) 
202. 3. MODIOLOPSIS FABA. 
Pu. LXXXII. Fig. 4. 
Reference pag. 158, pl. 35 of this volume. 
This species, which is abundant in the Trenton limestone, appears more rarely in 
the Hudson-river group. It is nevertheless often found associated with the preceding and 
following species, both in the shaly and arenaceous portions of the group. 
356. 16. MODIOLOPSIS? NUCULIFORMIS (n. sp.) 
Pu, LXXXII. Figs. 5 a, b. 
Subelliptical, length nearly once and a half the width; beaks elevated ; cardinal margin 
a little declining posteriorly ; front rounded ; ashallow sinus extending obliquely backwards 
from the beak to the base, producing an indentation in the basal margin; surface marked 
by concentric folds, which are undulated on the sinus. 
