TELLINA. TELLEN. 
176 
tliat 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 Tellcn. 
Lister, pi. 297- f. 134 — Montagu, pi. 2. f. 3 — Dorset Cat. 
ph 5. f. S. s 
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 
striae and a few larger ridges: iiiside white, but not glossy, 
clearer round the margin, with a faint appearance of lon¬ 
gitudinal striae: 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 Bantrv bay. v . v. 
22. Tellina lactea. White Tellen. 
Montagu , pi. 2. f. 4 — Dorset Cat. pi. 5. f. 9 ? 
Shell orbicular, flattivsh, 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 strim: 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 \ in the teeth $ and in having a 
heart 
