232 MOLLUSCA FROM THE CRAG. 
Spec. Char. Testa orbiculato-ovatd, tumidd soliduld ; anticé rotundatd, postice subangu- 
laté ; cardine bidentato, dentibus lateralibus nullis. 
Shell roundly ovate, tumid, thick, and strong; anterior side rounded, posterior 
somewhat angulated ; cardinal teeth two, lateral teeth none. 
Length, * inch. Height, = inch. 
Locality. Mam. Crag, Bramerton, Weybourne, Bridlington, Dalmuir, Russia, 
Canada. 
Recent, Britain, Baltic, N. E. Coast of America, Black Sea. 
I have not seen this shell from the Red Crag; as it is, however, an estuary species, 
it is less likely to be there. In the recent state, it is often found high up in our rivers, 
where the water is nearly fresh when the tide is out. The shells grow large and 
thick in muddy localities, and thinner and more delicate in sandy places. 
Tellina, is probably its most appropriate place, although the entire absence of lateral 
teeth does not strictly accord with the diagnosis of this genus, but it corresponds with 
it in all other respects. 
Fig. 1a, 6, is the representation of a shell from Clacton, where I obtained it from the 
Clay in which Unio “ittoralis is found in abundance; and upon some of my specimens of 
Unio are several barnacles, evidently showing the close proximity of the sea to this 
fresh-water deposit when it was formed.* 
I have myself obtained only few specimens of the fossil from Norfolk, but I am 
informed it is not rare. 
8. TELLINA FABULA, Gronovius. Tab. XXI, fig. 3. 
TELLINA FABULA. Gron. Zoophyl. Gronov., p. 263, No. 4, pl. 18, fig. 9, 1781. 
— —_— Phil. Enum. Moll. Sic., vol. i, p. 26, t. 3, fig. 10, 1836. 
— — Lyell, Mag. Nat. Hist., vol. ii, new series, p. 327, 1839. 
oa _ G. B. Sow. Thesau. Conch., vol. i, p. 287, pl. 57, fig. 62. 
— — Forb. and Hanl. Hist. Brit. Moll., vol. i, p. 302, t. 19, fig. 9. 
—  opiscors. Pulteney. Hutchin’s Dorset, p. 54. 
— SEMISTRIATA. Solander, ex Montague. 
Spec. Char. “Testa elongato-ovatd, compressa, transversd subinequilaterali, tenui ; pos- 
tice attenuata, subrostratd, anticé majiore rotundatd ; valvula sinistra levi, dextrd obliqué 
striata ; cardine bidentato, dentibus lateratibus parvis.” 
Shell transversely elongato-ovate, compressed, sub-inequilateral, thin; posterior 
side narrow, and somewhat pointed ; anterior broader, larger, and rounded; left valve 
* At Clacton I have also obtained Mytilus edulis, Cardium edule, and Trigonella plana, and also a 
rolled specimen of Melania inquinata (Cerithium melanioides, Sow.). 
