173 TELLINA. TELLEN. 



that in the right hand valve more solid and remote : length 

 an inch and three quarters ; breadth as much. 



This may possibly be one of the varieties of T. crassa. 



At Weymouth : very rare. 



21. Tellina rotundata. Round Tcllen. 



Lister, pi. 297. f- 134 Montagu, pi. 2. f. 3 Dorset Cat. 

 pi. 5. f. 8. 



Shell very convex, orbicular, often produced at the an- 

 terior side, and a little flexuous in the circumference, thin, 

 semitransparent, chalky or yellowish white, and generally 

 covered with a brownish skin, with fine irregular transverse 

 strijje and a few larger ridges; inside white, but not glossy, 

 clearer round the margin, with a faint appearance of lon-^ 

 gitudinal stria? : beaks nearly central, prominent, pointed, 

 hardly inclining to either side, without any heart-shaped 

 depression under them : hinge with two teeth in each 

 valve, one of them cloven, the other somewhat diverging, 

 and a slight groove which runs in nearly a straight direc- 

 tion from the beak along the posterior margin : diameter 

 an inch. 



Western coasts, and Bantry bay. v. v. 



22. Tellina lactea. White Tellen. 



Montagu, pi. 2. f. 4 Dorset Cat. pi. 5. f. 9 ? 



Shell orbicular, flattish, thin, yellowish-white, often co- 

 vered with a brownish skin, irregularly striate transversely ;. 

 inside dull chalky-white, clearer round the margin, with a 

 faint appearance of longitudinal striaa : beaks central, pro- 

 minent, pointed, turning to one side, with a slight oval de- 

 pression under them : hinge with a single entire tooth in 

 one valve, locking between two simple divaricate ones in 

 the other, and a deep furrow which runs obliquely from 

 the beak on the anterior side in each valve : diameter three 

 quarters of an inch. 



This species is very rare, and distinguished from the last, 

 in being much flatter and more regularly rounded in the 

 circumference; in the deep oblique furrow which runs from 

 the teeth along the cartilage margin withinside, which is 

 totally wanting in the last j in the teeth j and in having a 



heart 



