﻿NEW CRETACEOUS FOSSILS. 329 



off as represented in the figures, but the remainder perfectly preserved, and the 

 hinge is as entire as that of a recent bivalve. It differs from 0. solenoides, in having 

 an anterior wing with a truncated margin ; in being much more compressed, and in 

 having an uninterrupted series of prominent cardinal teeth, &c. 



CTENOIDES, Klein.— LIMA, Brug. 



Ctenoides acutilineata. PL 34, fig. 2. Oblong, oblique, very thin ; posterior side 

 radiated with acute, prominent lines, thirteen to fifteen in number ; anterior side with 

 minute, close, radiating lines ; surface concentrically wrinkled ; posterior margin sub- 

 rectilinear. 



This somewhat resembles L. Wacoensis, Eoemer, in outline, but it is less ventricose, 

 and has radiating lines, whilst the other is costate. 



Klein founded this genus on the shell known as Lima glacialis, and the L. scabra is 

 the type of his genus Radula. 



INOCERAMUS, Parkinson. 



1. Inoceramus argenteus. PL 34, fig. 16. Obliquely suboval, very thin, smooth, 

 inflated anteriorly; umbo prominent; summit elevated; lines of growth towards the 

 posterior margin assume the form of squamose striae ; anterior side very short ; mar- 

 gin obtusely rounded. 



2. Inoceramus costellatus. PL 34, fig. 12. Obliquely subovate, ventricose ; radii 

 slightly prominent, rounded, close, disappearing posteriorly, obsolete towards the 

 anterior margin; concentric acute lines ornament the surface; anterior side very 

 short, obtuse ; umbo and beak of larger valve very prominent. 



This species is marked exteriorly like a Pholadomya, but is inequivalve, with the 

 hinge of an Inoceramus. The specimen is distorted. 



Species of this genus were figured by Klein in 1770, under the generic names of 

 Spondiolithos, Musculites and Pholadis. 



OSTREA, Lin. 



Ostrea peculiaris. PL 34, fig. 7. Oblong or elliptical, thin, ventricose along the 

 middle and depressed on the sides ; surface with radiating wrinkles ; margins towards 

 the apex denticulated. 



A thin and abundant species remarkable by the tuberculated or denticulated mar- 

 gins and elongated trilobe shape. 



2. Ostrea confragosa. PL 34, fig. 4. Very irregular ; rather thin ; lower valve 

 profoundly ventricose, with deep irregular cavities or depressions. 



The lower valve only is known, and is very unlike any other Cretaceous species in 



the United States. 



84 



