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ceecled by granite. In another direction, they are lost in the lime-stone 

 rocks of Ghudleigh. 



The stratum qf shells, Mr. Scammell observes, exists in a stratum of 

 greenish yellow sand, about five feet below the surface ; and he is able, 

 from repeated and careful observation, to state that these fossil shells 

 extend upwards of four miles. 



The shells, from their extreme brittleness, are almost all in small frag 

 ments. Mr. Scammell having, however, kindly furnished me with some 

 of the largest, I was enabled to ascertain that they were the remains of 

 several species of Pectens, of a small oblong oyster, and of a shell, in 

 which, although the characters of a chama were predominant, only one 

 mark of attachment was discoverable. 



The general form of this shell is very much like that of the chamse we 

 have been just describing : the outer surface is pretty smooth, being only 

 marked by faint transverse striae. The hinge is formed by an oblique, 

 moderately sized, and slightly crenulated tooth, on the flat valve, which 

 is received by an oblique groove, with correspondent crenulse on the 

 convex valve. 



CXXX1V. Spondylus. A rough, slightly-eared, inequivalved bivalve, 

 with unequal beaks; the inferior more produced, truncated upwards, 

 and with ene groove. The hinge with two thick recurved teeth, with 

 an intermediate pit for the reception of the cartilage. One muscular 

 impression. 



Lamarck describes only one species, S. radula, as found in the environs 

 of Paris. A fossil shell of this genus, which, from the appearance of its 

 matrix, I suspect to be from Worcestershire, agrees, except in its size 

 being one third larger than the French fossil, with the species described 

 by Lamarck. It is slightly eared, and the inferior valve is marked with 

 rough longitudinal striae. It is rough, oblique, and of an oval orbicular 

 form. The stronger and most raised of the striae of the lower valve have 

 small spinous squamse placed at about half an inch distant; these strise 

 being separated by from six to nine small granular strise. 



