PANDORA. 209 



side of only about one quarter the length of the produced 

 posterior one. The front dorsal edge, at least in the less 

 shallow valve, is convex, and moderately declining ; the 

 hinder dorsal edge is more or less (but not profoundly so) 

 concave, and slightly, yet decidedly sloping. The front 

 is the broader extremity, and is subangularly rounded ; 

 the hinder is much attenuated, but not very acutely beak- 

 ed, as there is no distinct ventral inflection beneath it, and 

 the tip is obtuse, more or less squared above, and not very 

 projecting or ascending. The front hinge margin of the left 

 valve is externally sharp, and elevated above that of the 

 other ; the hinder of the right valve, as is usual in the 

 genus, is flattened down, and overlaps that of the other; 

 but is not concave, nor at all excavated. The umbonal 

 ridge is best indicated in the more convex valve, where two 

 rather broad and approximate elevated lines run from the 

 beaks to its extremity, becoming more obtuse as they ad- 

 vance ; corresponding, but very feeble grooves, are visible 

 in the opposite valve. 



The most elongated specimen we possess is an inch and a 

 third in length, and five-eighths of an inch in breadth ; the 

 widest is a trifle more broad, and the sixth of an inch less 

 in length. 



The animal is figured by Poli, and represented as having 

 yellowish-brown tubes. 



Although by common report ascribed to Weymouth and 

 South Devon, we have no certain testimony of its being 

 found in any of these spots ; it is, however, abundant on 

 the sandy shores of Gorey and St. Helier, in Jersey (S. H.); 

 Guernsey (Clark). It occurs fossil in both red and coralline 

 crags (S. V. Wood), and ranges at present to the Mediter- 

 ranean. 



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