216 MOLLUSCA FROM THE CRAG. 
Cytuerna Lincta. Lam. An. sans Vert., t. v, p. 573, 1818. 
= — ? Basterot. Bord. Foss., p. 90, pl. vi, fig. 10, 1825. 
— — Phil. En. Moll. Sic., vol. i, p. 41, vol. ii, p. 32. 
== = Dujard. Mem. Soc. Geol. de France, t. ii, part ii, p. 260, 1837. 
= — Bronn. Leth. Geogn., p. 955, t. xxxvili, fig. 4 a—e, 1838. 
— sinuaTa. Turt. Brit. Biv., p. 163, 1822. 
Asa LINEATA. Leach, MSS. Defrance, Coll. ex Basterot. 
Exoteta tincta. Brown. Ilust. Brit. Conch., pl. xx, fig. 4, 1827. 
ARTEMIS — Forbes. Agean. Invert. Rep. Brit. Assoc., p. 180, 1843. 
— — Lovén. Ind. Moll. Seand., p. 39, 1846. 
— — Forb. and Hanl. Hist. Brit. Moll., vol. i, p. 431, pl. xxviii, figs. 5, 6, 1848. 
—  sinuata. 8S. Wood. Catalogue, 1840. 
— compra. Lovén. Ind. Moll. Scand., p. 39, fide Alder. 
ARTHEMIS LINcTA. Agassiz. Icon. des Coq. Tertiares (Extr. des Nonv. Mém. de la Soe. 
Helv. des Se. Nat., tome vii, 1845,) p. 22, t. ili, figs. 11—14. 
Dosinta tinota. Gray. List. Brit. Moll., p. 4, 1851. 
Lister. Hist. Conch., lib. ii, fig. 126. 
Spec. Char. Testé suborbiculari, lentiformi, subinequilaterali, concentricé striata, 
striis numerosis, confertis levibus ; lunuld cordatd impressd. 
Shell suborbicular, lentiform, subinequilateral, fragile, covered with numerous 
close set striz: lunule heartshaped ; impression of the mantle with a deep tongue- 
shaped sinus. 
Diameter, 13 inch. 
Localities. Cor. Crag, Sutton, Ramsholt. 
Red Crag, Walton-on-the-N aze. 
Recent, Mediterranean, British and Norwegian Seas. 
Not very rare either in the Coralline or in the Red Crag, but the specimens are in 
general extremely fragile and very difficult to procure ; they are much thinner than 
those of the preceding species, and appear to have less of animal matter remaining ; 
although this is much less abundant than J. /entiformis, it appears to present a greater 
diversity of character in the outline, and I have thought it necessary that two forms 
should be represented: where individuals have become more elongated than what 
might be considered as the normal form of the species the shell is invariably more 
convex or tumid, so that an equal quantity of space is occupied by the animal. 
It is said in the recent state in the British seas to have a range in depth varying 
from low water mark to the depth of sixty fathoms. 
Mr. Smith, of Jordan Hill, enumerates Cytherea exoleta in his Catalogue of Shells 
from the Clyde Beds. Mem. Wern. Nat. Hist. Soc., v 1. vii, p. 45, 1838. 
