BIVALVIA. 95 
7. Lepa pyemma, Minster. Tab. X, fig. 11, a—dé. 
Nucuta pyamma. Munst. Apud. Goldf. Pet. Germ., vol. ii, p. 157, t. 125, fig. 17. 
— _— S. Wood. Mag. Nat. Hist., New Series, vol. iv, p. 298, pl. 14, fig. 7, 
1840. 
—_— — Phil, En. Moll. Sic., vol. ii, p. 46, 1844. 
— — Middendorf?. Mem. de l Acad. Imp. de St. Petersb., p. 544, 1849. 
—  rpposa. Smith. Mem. Wern. Soc., vol. viii, pl. 2, fig. 10, 1838. 
— corsputorprs. Id. in addendum. 
— meNnuis. PAil. En. Moll. Sic., vol. i, p. 65, pl. 5, fig. 9, 1836. 
— — Jeffreys. Ann. Nat. Hist., vol. xix, p. 313. 
— wenticuta. Méll. Ind. Moll. Groenl., p. 17, 1842. 
— Purirrrana. Nyst. Coq. Foss. de Belg., p. 224, pl. 17, fig. 5, a—e, 1844. 
Lepa prema. Forbes. Mem. Geol. Surv., vol. i, p. 419, 1846. 
— — Ford, and Hanl. Hist. Brit. Moll., vol. i, p. 230, pl. 47, fig. 10, and 
pl. P, fig. 3, 1849. 
Yotp1a pyamma. Lovén. Ind. Moll. Scand., p. 35, 1846. 
Spec. Char. Testié minutd, ovato-trigonuld, subequilatera; tumidd, levigatd, politd, 
clausd ; antice ovato-rotundatd, postice subrostratd ; lunuld indistinctd ; margine inte- 
gerrimo. 
Shell small, triangularly ovate, subequilateral, gibbous, smooth, glossy, and closed ; 
anterior side roundedly ovate; posterior subrostrated, without a distinct lunule ; 
margin very smooth. 
Longitudinal diameter, 4th of an inch. 
Locality. Cor. Crag, Sutton, Ramsholt, Gedgrave. 
Clyde Beds. Recent, Mediterranean? Britain, Scandinavia. 
This species is found in several localities of the Coralline Crag, and very abundantly 
at Sutton. It may be further described as having a very broad hinge line furnished 
with 8 to 12 teeth on each side of the umbo, they are angular, large, and promi- 
nent in the centre of the area and towards the sides, with large interspaces for 
the interlocking of the teeth of the opposite valve, by which the two valves are 
often found in conjunction. The shell is very tumid, moderately thick and strong, 
and perfectly closed all round, it has a somewhat prominent umbo, and is without any 
defined lunule or corselet; the posterior side is generally though not always the 
larger, and its termination rather acuminated and a little curved upwards: the 
fossette for the ligament is very small, and the muscle marks not in general deeply 
impressed or well defined; that by the mantle has a small sinus. The shell is glossy 
both within and without, and slightly nacreous. My Crag specimens are small, not 
exceeding the sixth of an inch in the transverse or greatest diameter; but a few 
specimens from the Clyde Beds, obligingly given to me by James Smith, Esq., of 
Jordan Hall, appear to have attained larger dimensions, and are rather less equilateral. 
This shell is given by Philippi, on the authority of Scacchi, as a species living 
in the Mediterranean, and it is also found fossil in the Upper Tertiaries of that part 
of the world. 
