164 ARCADE. 



This shell, known to me as a fossil only, proves to be living abun- 

 dantly in more northern seas, and has been described in Europe 

 under the specific name buccata. It varies considerably in its pro- 

 portions, so that MciUer has designated two varieties, viz., — var, 

 brevis: ovate, ventricose, lower margin strongly arcuate ; var. Iccvior: 

 moderately ventricose, greenish yellow, rather smooth. It is more 

 ventricose, less elongated and more finely sulcated than L. pernula. 



Leda minuta. 



Shell pear-shaped, beaks tumid, rostrum very short, scarcely upturned, and 

 squarely truncate, epidermis dusky. 



Area minuta, Fahr. Fauna Gr. 414. — Gmel. 3309. 



Area minuta Gra;nlandica, Cheain. Conch, x. 351, figs. 1657, 1658. 



Nucula purva, Sowerby, Conch. 111. No. 12, fig. 7. — Reeve, Conch. Syst. pi. 85, fig. 7, 



— H\NT>EY, Brit. Biv. 169, pi. 19, fig. 52. 

 Nucula minuta, PniLipn, Zcits. f. Malac. 101 (1844). 

 Nueulana minuta, jNIorch, Prod. Moll. Groenl. 21. 

 Leda minuta, Moller, Ind. MoU. Grojnl. 17. — Hanlev, in Sowh. Thes. iii. 114, pi. 228, 



figs. 61, 62. 



Shell oblong, pyriform, tumid, beaks at anterior third, slightly 



elevated, ol)tuse, inclined inwards, anterior dorsal margin sloping so 



as to bring the somewhat acutely rounded point about midway to 



the base ; posterior dorsal margin with about the same 



FiR. 470. . . 



slope as the front, direct and slightly upturned very 

 near the tip, which is very small and squarely truncate ; 

 ventral margin full and well-rounded, with a very slight 

 emargination under the tip ; dorsal face very broad, 

 with a wide, flattened, or somewhat depressed space, des- 

 titute of riblets, in front of the beaks, and a long lance- 

 olate one defined by a sharp ridge behind ; disks of the valves 

 very tumid, with a shallow sub-marginal channel behind ; surface 

 deeply grooved concentrically, so as to form conspicuous reflexed 

 riblets, which terminate on reaching the dorsal areas ; epidermis 

 dusky chestnut. Interior slightly nacreous, showing the external 

 riblets, with a very distinct sharp ridge running from under the 

 beaks to the middle of the tip ; hinge with a very small, oblique lig- 

 ament pit, with aliout twelve teeth before and fourteen behind it. 

 Length, one half inch ; height, three tenths of an inch ; breadth, 

 one fourth of an inch. 



Sent to me in considerable numbers from Halifax, hy Mr. Willis. 

 No little confusion in the synonymy of this shell, in consequence 



