314 



vex, dull whitish (internally pure white), covered by a thin ash- 

 coloured fugacious epidermis ; ventral margin more or less convex ; 

 front dorsal edge arched and slightly sloping, lrinder one straight 

 and greatly sloping; posterior side short, subangulated below; 

 anterior extremity rounded ; beaks usually eroded ; ligament large 

 and prominent ; fold almost obsolete ; one of the teeth bifurcate 

 (when the hinge is perfect, which is rarely the case) in each valve. 

 Boston, (Goidd) ; Arctic Ocean. 



181. Tellina calcarea (pi. lxii. f. 183.) Chemnitz, vol.vi. 

 p. 140. f. 136 ; Dillwyn D. Cat. p. 93 ; Haid. Des. Cat. p.46. t.4. 

 f. 43 ; T. sordida, Phil. Ab. mid Bes. Conch, part 9. t, 5. f. 6. 



T. testa ovata aut subovata, solidiuscula, subina?,quivalvi, con- 

 vexiuscula, iuEequdaterali, extus intusque albida, epidermide cine- 

 rascente induta, sublsevigata ; margine ventraH satis convexo, 

 postice accliuato; dorsaH antice convexo et subdechvi, postice 

 declivi et subrecto ; latere antico longiore, ad extremitatem rotun- 

 dato ; postico obtuse cuneiformi ; natibus acutis, prominentibus ; 

 costa mnbonah satis distincta; fiexma ventrah subinconspicua, ; 

 ligamento magno, prominulo ; dentibus parvis. 



More or less ovate, moderately firm, very slightly inequivalve, 

 tolerably convex, inequilateral, whitish both within and without, 

 never polished but often slightly glossed, covered with an ashy 

 epidermis, under which it is nearly smooth or merely marked with 

 the lines of growth ; ventral edge ascending behind, moderately 

 convex; anterior side the shorter, rounded at its extremity, its 

 dorsal edge convex and somewhat sloping, but near the acute and 

 prominent beaks slightly incurved ; hinder side obtusely wedge- 

 shaped, the liganiental edge nearly straight ; mnbonal ridge tole- 

 rably evident ; the ventral sinus almost obsolete ; ligament large 

 and moderately projecting. 



Iceland and Greenland. 



182. Tellina nasuta (pi. lxiv. f. 224.) Conrad, Jour. Ac. 

 Nat. Sc. Philad. vol. vii. p. 258 ; Hani. Des. Cat. p. 71. sup. 1. 14. 

 f.7. 



T. testa, ovato-oblonga, solida, insequilaterali, convexa, impolita, 

 subkevigata, albida, epidermide cinerascente plerumque induta; 

 margine ventrali medio subretuso ; dorsali antice convexo paulu- 

 lumque declivi, postice elongato recto et declivi ; latere antico bre- 

 viore, rotundato ; postico cuneiformi ; extremitate postica, subbi- 

 angulata ; natibus obtusis ; lunula nulla ; fiexura costaque um- 



