﻿NEW CRETACEOUS AND EOCENE FOSSILS. 279 



Locality. — Eufaula. Mr. Tuomey's collection. Tippah Co., Alabama. Dr. Spill- 

 man. 



CRASSATELLA, Lam. 



Crassatella lintea. PI. 46, fig. 5. Subovate or subtriangular, convex, inequi- 

 lateral; disk concentrically ridged and finally striated, slightly contracted near 

 the umbonal slope, which is rounded ; posterior extremity subtruncated ; apex 

 slightly prominent ; posterior dorsal line nearly straight, very oblique ; margin within 

 finely crenulated ; lunule long and lanceolate. 



Locality, — Alabama. Tuomey's collection. 



Accompanies C. vadosa, and nearly related to it, but numerous specimens of each 

 compared showed a specific difference. It is thinner, less cuneiform posteriorly, and 

 differs in the fine raised concentric lines, &c. 



Crassatella pteropsis. PI. 46, fig. 9. Aliform, very inequilateral, convex ante- 

 riorly, posteriorly contracted ; umbonal slope slightly carinated below the umbo ; 

 posterior side rostrated ; surface with minute, concentric, impressed lines, very fine 

 and closely arranged on the umbo and summit ; margin within finely crenulated. 



Locality. — Tippah Co., Mississippi. Dr. Spillman. 



This species has nearly the outline of C. aliformis, Conrad, an Eocene shell, 

 but it is rather more nearly cuneiform posteriorly, and can be distinguished at a 

 glance by the minute grooves or lines on the umbo, which are large in the former 

 species. 



LINEARIA, Conrad. 



Oval or oblong ; cardinal teeth in the left valve two, the anterior one elongated, 

 very oblique, the other under the apex small and bifid. 



This shell, of which I have only the right valve, belongs to a Cretaceous group, 

 which D'Orbigny has referred to the genus Arcopagia of Brown ; but they appear 

 to me widely different, and certainly the hinge does not warrant their association 

 with Brown's genus. They are rather small bivalves, radiated posteriorly with 

 crenulated lines, and having closely arranged concentric lines. 



Linearia metastriata. PI. 46, fig. 7. Oblong-oval, convex, subequilateral ; pos- 

 terior end subtruncated ; disk with fine concentric lines and distinct radiating lines 

 anteriorly, and larger crenulated radii posteriorly ; the rest of the surface with 

 microscopic radiating lines ; cardinal tooth under the apex widely bifid ; lobes small 

 and slender. 



Locality. — Eufaula, Alabama. Tuomey's collection. 



The shell is thin and fragile, with a very slender cardinal plate. Arcopaqia can- 



71 



