234 MOLLUSCA FROM THE CRAG. 
This species is exceedingly abundant in the Coralline Crag, but I have seen it only 
in one locality. The palleal impression is very large and deep, extending inwards 
until it almost touches a sort of ridge or thickening of the shell between it and the 
impression of the anterior adductor; the lateral teeth are at unequal distances: two 
obtuse ridges diverge from the umbo to the ventral margin on the siphonal side, most 
distinct in the right valve, upon the interior of full-grown specimens; in the left, these 
markings, instead of being in relief, are impressed. Upon some of my fossils there are 
the remains of continuous coloured bands, not intercepted by white radiations. None 
of my Crag specimens have attained to so great a magnitude as is given to the recent 
British shell, my largest scarcely reaching three fourths of an inch in length. This has 
been well named : it strongly resembles a Donaz im all its characters. 
A specimen, in the cabinet of Sir Charles Lyell, has the locality of Bramerton 
attached to it. 
10. TeELuina ponactLua, 8. Wood. Tab. XXII, fig. 6, a, 6. 
TELLINA DoNACILLA. S. Wood. Catalogue, 1840. 
Spec. Char. Testd transversd, ovato-oblongd, subinequilaterali, compressiusculd, polita ; 
postice breviore, truncata, biangulatd ; anticé rotundatd ; cardine bidentato ; dentibus late- 
ralibus duobus. 
Shell transverse, ovately oblong, somewhat inequilateral, compressed, glossy ; 
posterior side the shorter, truncated, and biangulated; anterior side rounded ; two 
cardinal, and two lateral teeth. 
Length, inch. Height, 3 inch. 
Locality. Cor. Crag, Sutton. 
This shell appears to be rare, one specimen of each valve, in my own cabinet, are 
all that I have as yet seen. It very much resembles in outline 7. Oudardii, Payr., ‘ Moll. 
Cors.,’ p. 40, pl. 1, fig. 16—18, and I had considered it different, in consequence of 
the want of the peculiarly characteristic marks of that species, which has the exterior, 
as stated by the author, beautifully ornamented with lozenge-shaped cancelle, formed 
by radiating striee intersecting the lines of growth. If these lines be upon the 
recent shell and not alone in the epidermis, our fossil does not possess them. The 
surface is covered with some broad and flat obsolete ridges on the body of the shell, 
which are sharp and elevated upon the posterior slope. It is flatter than 7: donacina, 
less inequilateral, and has not the fine and regular strie of that species. It also 
somewhat resembles the figure of 7. compressa, Broc., pl. 12, fig. 9; and may possibly 
belong to one of the Mediterranean or Subappennine species, but I have not been able 
to obtain specimens for comparison. 
Our shell has two diverging cardinal teeth in the right valve, with one large, 
