14 BOOK OF SPECIES. 
cransverse 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. rornicaTA. 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...2. W. 
37+ 10. 
C. PORCELLANA. Oval-depressed; 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...3. W. 
37. 9. 
