ARC A. ARK. 11 



lower angle, which is the reverse in A. Nose : it is also en- 

 tirely destitute of the zigzag diagonal brown markings :. 

 length half an inch ; breadth an inch. 



West of England, and Scotland : rare. v. v. 



9. Area minuta. Minute Ark. 

 Walker, f. 81 Dorset Cat. pi. 1. f. 16. 

 Area caudata. Donovan, pi. 78. 



Shell oblong, much produced at one end which is angular 

 sloping and truncate, the other end rounded, finely striate 

 transversely, with three or four strong concentric ridges : 

 beaks small, turning a little to the longer side, with a smooth 

 cavity between them : teeth in a curved line, separated 

 by a hollow : length hardly three lines ; breadth about 

 four. 



Sandwich, Scotland, West of Ireland : rare. v. m. 



1 0. Area rostrata. Elongated Ark. 

 Montagu, pi. 27- f. 7- 



Shell somewhat oval, the smaller end sloping and elon- 

 gated into a lip which is turned up, the other rounded, 

 wrought with extremely fine regular slightly reflected 

 transverse.ridges, which are angularly turned across a few 

 slight longitudinal ribs from the beaks to the smaller end : 

 beaks small, nearly central, almost close together : teeth in 

 a curved line, angular, numerous on each side the beak, and 

 separated by a hollow : color pale horny, glossy, some- 

 times covered with a greenish skin, inside semitransparent 

 and finely polished : length half an inch - 9 breadth three 

 quarters. 



St. Abb's Head, Scotland : very rare. 



11. Area tennis. Thin Ark. 

 Montagu, pi. 29. f. 1. 



Shell somewhat heart-shaped, produced on one side and 

 rounded at the margin, white or covered with an olive 

 j skin : beaks small, not central, slightly inflected towards 

 ! the shorter side ; inside smooth, white, and somewhat per- 

 I laceous ; the margin thin : hinge with about fifteen teeth 

 placed in a curved line within the margin, six on one side 

 and nine on the other, divided by u small concave plate pro- 

 jecting 



