SUPPLEMENT TO THE BIVALVIA. 5 
3. Cyrena cunzIFrormMis, J. Sowerby. Tab. A, fig. 3 a—e. 
Cycias cuneIrormis, J. Sow. Min. Conch., t. 162, figs. 2, 3, 1817. 
CYRENA —_ Desh. Coq. foss. des Env. de Par., vol. i, p. 122, pl. xix, 
figs. 1, 2, 20, 21, 1824. 
— —_— Sandb. Land- und Siissw.-Conch., p. 181, t. viii, figs. 6 a, 0, 
1872. 
= — Morris. Catal. Brit. Foss., 2nd edit., p. 199, 1854. 
= — J. Lowry. Chart. Brit. Tert. Foss., pl. iv, 1866. 
— DONACIALIS, Desh. Dict. Class. d’Hist. Nat., t. v, p. 290, 1824. 
Spec. Char. C. Testé transversd, trigonuld, inequilaterali, irregulariter substriata ; 
antice truncata, postice angulatd ; dentibus cardinalibus tribus, dentibus lateralibus inequali- 
bus perpendiculariter rugosis aut striatis. 
Length, +%ths of an inch; height, ths of an inch. 
Localities. Britain: Charlton, New Cross, Dulwich. 
France: Lignites, and Sables moyens. 
This is an abundant species in the Woolwich beds of this country; and it is said by 
M. Deshayes to be profusely spread in the Lignites and Sables moyens in France. ‘The 
locality of Headen Hill is given in the ‘ Cog. Fos. des Env. de Par.,’ lab. 1, p. 128, but 
TI have not been able to see a specimen of this species from the Isle of Wight, nor have 
I heard of its having been found there. Possibly C. seméstriata may have been mis- 
taken for it. ‘The impression by the mantle exhibits a small and shallow sinus. 
The variation in this species consists in an extension of the siphonal side, one variety 
being more inequilateral than the other. It somewhat resembles the recent species 
Cyrena Moridensis. 
4. Crrena stricosa, S. Wood. ‘Tab. A, fig. 4. 
Spec. Char. C. Testd transverse trigonatd, inequilaterali, regulariter circinataé vel 
striata, striis maynis acutis, anticé rotundald, postice angulatad elongatdé; dentibus 
cardinalibus tribus, dentibus lateralitus striatus. 
Length, 12ths of an inch nearly; eight, }ths of an inch nearly. 
Locality, Charlton. (S. Wood.) 
This species is equally abundant with C. cvneiformis. It has the exterior covered 
with regularly concentric strize or ridges, rounded and distinct ; whereas in cexneiformis 
the lines of growth are indistinct or irregular, and sometimes scarcely perceptible ; and 
these differences appear to me to justify a specific separation. ‘The angular ridge over 
