368 MARSHALL: ADDITIONS TO “‘ BRITISH CONCHOLOGY.” 
in fresh water. The largest come from Torbay, and are 
14 inches in diameter. 
Var. eequalis Jeffi—Herm and Guernsey; Scilly (Smart 
and others). This variety is smaller and has an angular 
outline. L.0°8, B.o’9. 
Tellina balaustina L.—Peterhead, 30 miles off, in 60f., a 
fine living specimen and two valves (Dawson); Scilly, 4of. 
(Burkill and J.T.M.) ; the Minch off Loch Boisdale, 45 f.; 
Dornoch Frith, two young specimens. 
The young a line in breadth are depressed, inequilateral, 
and angular at the posterior side, somewhat resembling the 
same stage of Z: crassa, but the sculpture is much finer. 
It is still more like the young of Gastrana fragilis. 
T. crassa var. albida Jeff.—Equally diffused with the type. 
T. balthica L.—Our var. aéfenuata is the Baltic form, and in 
strict justice should be the type; but it is clearly a local 
and varietal form, and quite unsuitable for a type shell. 
Jeffreys’ figure is wrongly drawn, the rounded end appears 
the shortest, while it should be the contrary. Sowerby’s is 
perfect. The largest come from Laugharne and Pendine, 
and measure 14 inches in breadth. 
Var. attenuata Jeff.—Yellowish-white. Cumbrae (Brown); 
Dornoch Frith. 
Var. nivea Jeff.—Weston-super-Mare. 
T. tenuis DaC.—Sowerby’s two figures of this shell are excel- 
lent, but Jeffreys’ figure has the posterior end too produced; 
that end should be the shortest. 
T. fabula Gron.—Jeffreys’ dimensions are extreme, and his 
figure is too long or deep; it should be like Sowerby’s. 
These errors of figuring are clearly due to a non- 
adherence to types, of which sufficient care has not been 
taken by writers. Even Jeffreys, with all his care, fre- 
quently departs from his type figures in his detailed 
J.C., viii., Apr. 1897. 
