236 



ing species, is a little incurved and beak-formed; and its sinus, com- 

 mencing at this beak, is smooth and rounded, like that Cuspidatus; and 

 joins with its base, at the back part, the base of the convex wave of the 

 upper, or smaller valve, at a. 



I must acknowledge that the term foramen, or aperture, does not 

 seem applicable to the triangular cavity in either of these shells; it 

 appearing to be rather a deep triangular groove, in which might have 

 been fixed a strong muscle or elastic cartilage, the office of which might 

 have been to have drawn open the valves. This, however, is only con- 

 jecture. I shall therefore proceed, acknowledging that I have dwelt 

 longer on these two last species, from the expectation that it might lead 

 to the better understanding of the following genus. 



CLIII. Cnlceola. A regular inequivalved bivalve : the largest valve 

 being in the shape of the pointed end of a slipper, and the small one flat 

 and semicircular. The hinge with a central tooth, and four rugous pro- 

 jections at each end. 



This shell is very thick, and nearly an inch and a half in length. The 

 back of the large valve is flat, and marked with transverse linear striae, 

 which are continued over the rounded fore part. The upper valve is 

 striated concentrically. Plate XVI. Fig. 14, represents the upper, and 

 Fig. 15, the lower valve of this shell. 



It is placed by Gmelin at the end of the genus Anomia, as Anomia 

 sandalium. To this species, the only one which is known, Lamarck has 

 given the name of C. sandalina. It was first discovered in the duchy of 

 Juliers, by M. le Baron de Hiipsch, of Cologne, who gave a particular 

 description of it in a tract published at Francfort, in 1768, under the title 

 ef Nouvelles decouvertes faites dans Vhistoire naturelle de la basse Allemagne, 

 des petrificatiom de quelques animaux testaces rares etpeu connus, K c. M. Hiipsch 

 kindly distributed these fossils among the more intelligent collectors, 

 who were thereby enabled to form their respective opinions of these 

 extraordinary bodies. M. Hiipsch himself was of opinion that it was a 

 fossil, inequivalved, bivalve shell, the smaller exactly closing up the 



