52 CONTRIBUTIONS 



Observations. A single valve of this interesting species 

 has come into my possession. It is the left one. Its beau- 

 tiful form eminently distinguishes it. The exterior portion 

 of the valve is not perfect, and characters not observed on 

 this specimen may be, perhaps, found on perfect ones. 



E. Bucklandii. Plate 1. Fig. 21. 



Description. Shell sub triangular, somewhat inflated, 

 inequilateral, polished, obtusely angular before and at 

 top ; substance of the shell rather thin ; posterior and an- 

 terior slopes somewhat flattened; beaks somewhat ele- 

 vated, pointed, incurved ; cavity of the shell not very deep ; 

 inferior portion of the margin finely crenulate. 



Diam. . . . v" '< Length .7, Breadth 1, inch. 



Observations. Like the last described, a single valve 

 of this beautiful species only has been found. It was 

 taken out of a mass in about a dozen pieces and recon- 

 structed. It resembles the triangulata in many of its cha- 

 racters, but is more transverse, and is neither flat nor gib- 

 bous on the exterior. In outline, it has some resemblance 

 to a Donax. 



In dedicating this species to the distinguished author of 

 the " Reliquiae Diluvianse," I will take the opportunity to 

 make my acknowledgements for the pleasure and advan- 

 tages derived from his various writings. Few geologists 

 of Europe have, with the same success, cultivated the 



