134 PATELLA. LIMPET. 



rugged with plaits or scales irregularly folding over each 

 other, sometimes only transversely scaly : valves unequal, 

 one of them flat and entire, the other very convex ; inside 

 pearly white : beaks rather oblique, with a row of small 

 tooth-like knobs on each side : color generally dull brown. 

 Banks and beds at low water mark. v. v. 



13. Ostrea parasitica. Parasitical Oyster. Fig. 8. 



Shell somewhat orbicular, or inclining to oblong, flattish, 

 smooth and rather glossy, very obscurely wrinkled trans- 

 versely, of a paler or darker chocolate-brown color, some- 

 times inclining to yellowish-brown, with irregular reddish- 

 brown longitudinal waved lines disposed in the manner 

 of loose tufts j sometimes there is a single whitish stripe 

 from the hinge to the margin: beaks central, nearly 

 straight 5 inside glossy- white, purplish towards the hinge, 

 with afewdenticulations on each side the hinge: diameter 

 about an inch and a half. 



We find this species not unfrequently attached to the 

 claws of crabs, in Devonshire, and in Ireland on floating 

 timber, and evea on one another. Its habits therefore and 

 general appearance incline us to think it quite distinct from 

 the common oyster, v. v. 



PATELLA. LIMPET. 



Shell with a single valve, more or less conical 

 and shaped like a hason, and generally without 

 spire. 



A. Furnished with an internal appendage or partition, 

 1,2. 



B. With the crown entire) 3 to 16. 



C. With the crown perforated, 17 to 20, 



A. Furnished with an internal appendage or partition, 

 1,2. 



1. Patella Chinensis. Chinese Bonnet. Fig. 29, 30. 

 Lister, pi. 546. f. 39 Montagu, pi. 13. f. 4. 

 . Patella albida. Donovan, pi. 129. 



Shell 



