TRENTON LIMESTONE. 183 
Genus CARINAROPSIS. 
[Carinaria, and oLis; from its resemblance to CaRINARIA.] 
Character. Symmetrical, subconical, patelliform, subangulated or carinated on the dorsal 
line ; apex incurved or convolute ; aperture oval, narrowed posteriorly. 
There are two or three species of shells having the characters here given. They are 
usually associated in the rock with the Bellerophon bilobatus, and are rarely seen in any 
other situation. 
238. 1. CARINAROPSIS CARINATA (n. sp.). 
Pu. XL. Figs. 1 a, 0, c. 
Depressed conical ; apex incurved ; aperture broadly expanded, with a narrow sinus in 
the posterior dorsal margin, from which a strong dorsal carina extends to the apex ; surface 
concentrically striated. 5 
This species is remarkable for the broadly expanded aperture and sudden contraction 
towards the apex, which is acutely pointed and incurved. 
Figs. 1 a, 6. Lateral and dorsal views. 
Fig. 1 c. Lateral view of another specimen, showing a more elevated carina. 
Position and locality. In the dark compact limestone at Middleville and Trenton Falls, 
associated with the Bellerophon bilobatus. 
239. 2. CARINAROPSIS PATELLIFORMIS (x. sp.). 
Pu. XL. Figs. 2 a, b. 
Obliquely subconical, patelliform, the apex incurved and extended in a line with or 
beyond the margin, obtusely carinated upon the dorsal line ; aperture broadly oval, slightly 
narrowed posteriorly ; surface marked by fine concentric sublamelliform strie. 
This species resembles in form the recent Caputus ; but the structure of the shell is quite 
different, being, in this respect, closely allied to the BeLLEropnon. There are one or two 
other species in the Hudson-river group, and a single more elevated one in the Trenton 
limestone, which has not been satisfactorily determined. 
Fig. 2 a. Dorsal view. Fig. 2 6. Lateral view of the same specimen. 
This one and the preceding species are arranged in this connection, both from similarity 
in the structure of the shell to Bellerophon, and from an analogy in the form of C. carinata. 
Position and locality. In the compact finegrained limestone, with the preceding species, 
at Middleville. 
