MOLLUSCA FROM THE CRAG. 
nO 
rhe] 
2 
Trina Fervensis. Gmel. Syst. Nat., p. 3235, 1788. 
— — W. Wood. Linn. Trans., vol. vi, p. 174, t. 15, figs. 20, 21, 1802. 
mst RADIATA. Da Costa. Brit. Conch., p. 209, t. 14, fig. 1, 1778. 
— INCARNATA. Penn. Brit. Zool., vol. iv, p. 74, pl. 47, fig. 31, 1776. 
— MuRiIcATA. Broce. Conch. Subap., p. 511, t. 12, fig. 2. 
—  runcata. Spengler. Fide Lovén. 
— mrirasciaTa. Don. Brit. Shells, vol. ii, pl. 60, 1800. 
PsaMMoBIA FEerroEnsts. Lamk. Hist. Nat. des An. s. Vert., v, p. 512. 
= — Phil. En. Moll. Sic., vol. i, p. 23, pl. 3, fig. 7, 1836. 
= = Lovén. Ind. Moll. Seand., p. 42, 1846. 
— _ Sismonda. Syn. An. Invert. Pedm. Foss., p. 21, 1847. 
— Dumonti. Myst. Coq. Foss. de Belg., p. 103, pl. 4, fig. 12, 1844. 
— LAEVIS. Id. Coq. Foss. de Belg., p. 104, pl. 4, fig. 13. 
— murtcata. Id. Coq. Foss. de Belg., p. 105. 
_— — 2 Grateloup. Cat. Zool. des An. Vert. et Invert., p. 67, 1838. 
— arrinis? Dugard. Mem. de la Soc. Geol. de France, tom. ii, part 2, 
p- 257, pl. 18, fig. 4, 1837. 
Spec. Char. Testa transvervd, ovato-oblongd, subaequilaterali, tenui ; concentricé 
striata ; antice rotundatd ; postice truncatd, angulatd, striatd et decussatd ; margine 
veatrali convewiusculo ; sinu palliari magno. 
Shell transverse, ovately oblong, nearly equilateral, thin ; concentrically striated ; 
anterior side rounded ; posterior truncated, and decussated upon the posterior slope ; 
ventral margin slightly curved; palleal sinus large. 
Length, \Zinch. Height, {ths of an inch. 
Locality. Cor. Crag, Gedgrave, Sutton, and Ramsholt. 
Recent, Britain, Mediterranean, Finmark. 
This elegant shell, in its full-grown state, is rare; but small specimens and frag- 
ments are by no means scarce. I have assigned it, without a doubt, to the existing 
species, although some of my fossils appear rather more transverse, or have a some- 
what greater length comparatively than the recent shell. My Crag specimens are 
particularly thin and fragile, with scarcely a trace of any muscular impression. In 
some of the young specimens the radiating strize upon the angular slope of the pos- 
terior side are strongly marked with decussating lines. 
This is said to have been found fossil in the Drift beds of Lancashire and Ireland. 
2. PSAMMOBIA VESPERTINA, Chemnitz. Tab. XXII, fig. 2, a—d. 
Lux vesperina. Chemn. Conch. Cab., vol. vi, p. 72, t. 7, figs. 59, 60, 1782. 
SOLEN VESPERTINUS. Gmel. Syst. Nat., p. 3228, 1788. 
TELLINA VARIABILIS. Don. Brit. Shells, vol. ii, t. 41, fig. 2, 1800. 
—— Gant. Poli. Test. Sicil., pl. 15, figs. 19, 21, 23, vol. i, p. 41, 1791. 
— — Born. Test. Mus. Cees. Vind., p. 31, t. 2, figs. 6, 7, 1780. 
— ALBIDA. Dillw. Dese. Cat. Brit. Shells, vol. 1, p. 78, 1817. 
