216 UPPER, OR FLINTY CHALK. 



are not uncommon in the Lower chalk of Sussex ; but I have not seen a 

 perfect specimen. 



Tab. xxviii. fig. 2. A specimen from Plumpton. 



The shell represented in Tab. xxvii. fig. 3. has the acuminated beaks, 

 and oblique liinge of the present species ; but the ribs are more pro- 

 minent and numerous, and the valves more convex : it may, perhaps, here- 

 after prove to be specifically distinct. 



Locahties. Plumpton, Offham, Southerham. 



87. Inoceramus latus. Tab. xxvii. fig. 1 0. 



Valves convex near the beaks, flat and expanded towards the front ; 

 surface marked with distant transverse ridges, and numerous concentric 

 stri^ ; posterior slope smooth, depressed ? anterior side expanded ; hinge 

 obHque. 



This species equals I. Cuvieri in length and width, but is much 

 depressed, and is also destitute of the prominent costae by which that 

 species is distinguished ; fragments occur that are from eighteen to twenty 

 inches wide, and almost flat. The posterior side is smooth, and de- 

 pressed ? the anterior expanded ; when this part is broken ofl:', the valves 

 assume a triangular form, as in the example figured. The hinge is very 

 oblique. 



Tab. xxviii. fig. 10, exhibits the usual appearance of the specimens : 

 the figure is diminished three-fourths. 



Localities. Common in the Upper chalk near Brighton, Lewes, 

 OfFham, &c. 



88. Inoceramus Websteri. Tab. xxvii. fig. 2. 



Convex, smooth, with distant, irregular, transverse ridges ; beaks 

 rounded, posterior slope nearly flat ; anterior side expanded, hinge very 

 obhque. 



The valves are convex, the surface smooth, and the ridges placed at 

 unequal distances. The greatest convexity is near the beaks, from 

 whence the shell gradually becomes flatter, and expands as it approaches 

 the front. The posterior slope is small, and somewhat depressed, the 

 hinge side flat, and broad. 



