ARCA. ARK. 



dinally as hardly to be visible with the highest magnifying 

 powers : beaks not quite central, prominent, pointed, close 

 together ; teeth in a curved line, three or four on each 

 side j inside glossy, with the margin thin and very entire : 

 diameter the eighth of an inch. 



Specimens of this minute Area were first presented to 

 us by the Rev. Dr. Goodall, who we believe obtained them 

 from the Devonshire coast. They seem to differ from th 

 very young of A. pilosa, in their transparency, total want 

 of colored markings, in the circumference not being circu- 

 lar, and in not having the slightest appearance of teeth or 

 crenatures on the margin, v. m. 



6. Area Nose. Noah's Ark. Fig. 58. 



Lister, pi. 368. f. 2QS Donovan, pi. 158. f. 1, 2. 



Shell oblong, inclining to rhombic, rounded at one end, 

 elongated, narrower, and somewhat angular at the other, 

 the smaller end of each valve turning in to meet the other, 

 forming a sharp angle and a gape at the margin, regularly 

 and strongly ribbed longitudinally, and crossed with fine 

 transverse lines giving it a punctured appearance, and 

 sometimes marked with a few concentric ridges : beaks 

 nearer to one end, much separated by a deep rhombic space 

 which is smooth : color pale rufous-brown, with deeper 

 chesnut bands crossing the valves diagonally ; inside whit- 

 ish or tinged with brown ; the teeth placed in a straight 

 line : length about half an inch ; breadth rather more. 



Sam shores of Devon and Cornwall, Duubar, and Lelth 

 roads in Scotland, and Dublin bay : rare. v. m. 



7- Area perforans. P erf Grating Ark. 



Lister, pi. 235. f. 69. 



Area lactea. Pennant, pi. Gl. f. 2 Da Costa, pi. 11. 

 f. 5 Donovan, pi. 135 Dorset Cat. pi. 11. f. 5. 



Shell thin, convex, rhombic oval, generally rounded at 

 one end and more or less angular at the other, but varying 

 much in its depth and figure, with numerous close-set re- 

 gular raised longitudinal lines, which are finely beaded by 

 minute transverse stria?., and marked with deeper trans- 

 verse ridges ; covered when fresh with a dark-brown silky 

 skin which fringes the margin, under which it is of a rusty- 

 brown 



