180 MOLLUSCA FROM THE CRAG. 
7. AsTarTE OmMALuU, Delajonkaire. Tab. XVII, fig. 1 a—/. 
Astarte Omati. Lajonk. Not. Geol. env. d’Anv. (Mém. de la Soc. d’Hist. Nat. de Par.) 
tom. i, p. 129, pl. vi, fig. 1 a—e, 1823. 
— — Desh. Ency. Meth. Vers., t. xi, p. 77, No. 2, 1830. 
— -- Nyst. Rech., Coq. Foss. d’Anv., p. 7, No. 24, 1835. 
_— — Id. Coq. foss. de Belg., pl. 152, pl. ix, fig. 2a, 6, c, 1844. 
— rucara. Lajonk (not J. Sowerby). Loc. cit., tom. i, p. 130, pl. 6, fig. 5 a—e, 1828. 
= — Nyst. Rech. Coq. Foss. d’Anv., p. 7, No. 25, 1835. 
—  sipartiTta. J. Sow. Min. Conch., t. 521, fig. 3, 1826. 
—  oBionca. J. Sow. Min. Conch., t. 521, fig. 4, 1826. 
Crasstna Omattt. Desh. 2d edit. Lam., t. vi, p. 258, 1835. 
— BIPARTITA. Id. es 3 t. vi, p. 259, 1835. 
Astarts. Lyell. Manual of Elem. Geol., 3d edit., p. 165, fig. 149, 1850. 
Spec. Char. Testd variabile, interdim oblongo-ovatd sepé trigonali; sublevigata 
ant sulcatd, tumidd vel compressa, plurimim inequilaterali, postice longiore, subangulatd ; 
lunuld ovatd, profundé excavatd ; natibus acutis, semper sulcatis : marginibus crenulatis. 
Shell variable, sometimes ovately oblong, often trigonal, smooth or sulcated, tumid 
or compressed, for the most part inequilateral ; posterior side the longer, subangulated; 
lunule ovate, deeply excavated: umbones sharp, sulcated ; margin crenulated. 
Length, \3ths of an inch; eight, 14th ditto. 
Localities. Cor. Crag, Sutton, Ramsholt, Gedgrave. 
Red Crag, Sutton. 
This shell is exceedingly abundant in all parts of the Corallme Crag. Of all the 
species of this very variable genus found in the Crag, this is, “par excellence,” the most 
perplexing and difficult to determine. There is a fossil found in the Middle and Upper 
Tertiaries of America in which the variations in form appear even greater than in our 
Crag shell, as shown by a large suite of specimens in the Cabinet of Sir Charles 
Lyell, and that geologist, in his Paper upon the “ Miocene Tertiary Strata of Maryland, 
Virginia, and N. and §. Carolina,” published in: the ‘Proceedings of the Geological 
Society, 1845, vol. iv, part ili, p. 555, considers 4. vicina, A. arata, A. cuneiformis, 
A. obruta, A. perplana, of the American authors, to be varieties of 4. undulata, Say., in 
which opinion I fully concur; but he further says, “I have some specimens of 
A. bipartita from the Suffolk Crag, which agree perfectly with the American fossil, 
except that in the latter the sides of the hinge teeth are much more distinctly grooved. 
A few only of the English specimens exhibit a faint trace of this grooving.” In a 
species so exceedingly variable as this appears to have been in the seas of the Coralline 
Crag, and in the same, or at least in localities so little removed as those of Suffolk, 
where they are now found, it is difficult to say what effect localities so far removed 
as those of South Carolina might have produced upon an animal with sucha tendency 
to variation; there is scarcely a limit to be put to its specific range, and this ex- 
cessively variable character is perhaps an argument in favour of specific identification. 
