14 



BOOK OF SPECIES. 



transverse scales ; apex acute^ sub-incurved ; 

 margin crenated^ cup depressed : diameter 1. 



CREPIDULA. 



Ovate or oblong-ovate; convex on the back, and 

 concave within ; spire inclining to one side ; 

 aperture with a horizontal partition next the 

 spire, extending to nearly the middle of the 

 shell, 



C. FORNiCATA. Oval ; margin entire, and 

 the summit obliquely recurved, chestnut, with a 

 white spot on each side the apex, or white vari- 

 ously mottled, or longitudinally rayed with brown ; 

 internal partition concave, brown. 1 . . . j. W. 



37. 10. 



C. PORCELLANA. Oval-dcprcssed ; margin 

 entire, and summit recurved ) internal partition 

 flat, whitish or brownish, variegated with dark- 

 brown or red spots, or purplish undulated lines ; 



inside generally white and glossy. 1 

 37.9. 



W. 



