66 anatinidtE. 



Anatina striata, Gn.vT, Append. Beechey's Voy. t. 43, fijr- 3. 

 Lyonsia gibbusa, Hancock, Ann. Nat. Hist, xviii. t. 5. tigs. 11, 12. 



Shell ovate-quadrate, elongate, wedge-shaped, beaks at anterior 

 third, dirty-white, covered with a very thin epidermis, which is 

 raised into numerous fine radiating ridges which entangle parti- 

 cles of sand, &c. ; disk tumid ; posterior dorsal margin 

 rectilinear ; ventral margin nearly parallel to it, gently 

 curving upwards, tip broadly and squarely truncate ; 

 dorso-ventral ridge distinct, obtuse, the portion above it 



L. arenosa. , ^ 



compressed ; anterior dorsal margin at nearly a right 

 angle with the posterior, direct, joining the ventral margin liy a 

 very short turn ; anterior area broad and deep, lanceolate ; right 

 valve the smaller and most shallow. Interior shining white. Hinge 

 very delicate, the margins each side of the apical point only very 

 slightly thickened. Ossicle like ivory, narrow and elongate, with a 

 nick at one end and a spine at the other, and with a sharp ridge 

 along the middle of the concave face. Length, five tenths of an 

 inch ; height, three tenths of an inch ; breadth, two tenths of an inch. 



Inhabits Halifax and Fishing Banks ( Willis) ; Labrador (^Pack- 

 ard) ; Greenland (Moller") ; also fossil in Greenland. 



This shell differs from the more common L. Norveg-ica by its 

 short, wedge-shaped, inflated form, dingy exterior, and more finely 

 wrinkled epidermis, and want of brilliant pearly lustre. It is rarely 

 if ever found this side of the British Provinces. Middendorff unites 

 both this and L. hyalina with L. Norvegica. He could not have 

 seen this species. 



Ocnus A^ATIl^A, Lam. 1809. 



Shell sub-equivalve, gaping slightly; hinge with a prostrate, 

 spoon-shaped tooth in each valve to receive the cartilage, and a 

 small ossiculum resting in front of the teeth, usually removed with 

 the animal. 



Anatina papyracea. 



Fig. 28. 



Shell thin, fragile, white, rounded-ovate, inequipartite, the shorter part nar- 

 rowed and truncated ; tooth narrow, directed oblic[uely forwards. 



Anatina papyratia, Say, Journ. Acad. Nat. Sc. ii. 314. — Totten, Silliman's Journal, 



xxviii. 347, fig. 1. 

 Anatina papyrarm, Gould, Inv. Mass. 1st cd. 47. — Stimpsov, Shells of New England, 



22. -De Kay, Nat. Hist. New York, 235, pi. 31, fig. 300. 



