128 EOCENE MOLLUSCA. 
5. Lepa ospuata, S. Wood. Tab. XIX, fig. 10. 
Spee. Char. L. testé minimé, elongato-ovatd, oblatd, levissind, glabra, subequila- 
ferali ; pedi-regione tumidd ; siphone-regione compressiusculd, margine obtuse rostrata ; 
umbonibus prominulis. 
Shell small, elongately ovate, externally smooth and glossy, slightly inequilateral ; 
pedal region tumid and rounded; siphonal region compressed ; obtusely rostrated ; beaks 
slightly prominent. 
Length, id of an inch. 
Localities. Chalk Farm (Wetherell), Potter’s Bar (dwards). 
There are a few specimens in Mr. Wetherell’s cabinet, and also in Mr. Edwards’s, 
which very much resemble, in outline and general characters, LZ. partim-striata from 
Highgate and Clarendon; but they differ in having the exterior perfectly smooth and 
glossy, and appear to be quite free from the ridges which ornament the centre or ventral 
portion of the shell of that species. This species presents some resemblance to the variety 
L. prisca, from Highgate; but the shell is larger, and the stphoni-lateral margin is not so 
pointed. The specimens are too closely imbedded in the clay to permit of removal, 
and the interior is consequently mvisible. 
6. Lepa prisca Deshayes. Tab. XVII, fig. 4, a—d. 
Lepa prisca. Desh. An. sans Vert. du Bass. de Par., t. i, p. 830, pl. 65, figs. 15 —17. 
Spec. Char. L. “ testa minimd, obovatd, tumidd, levigald, politd, striis incrementi vir 
conspicuis ; antice rotundata ; posticé angulatd, acutd, cuneatd ; umbonibus submedianis, 
depressis ; lunula ellipticd ; dentibus 8—9 utroque angulatis ; marginibus tntegris.” 
Shell small, obovate, turnmd, or inflated ; smooth, glossy, with scarcely visible lines of 
growth ; one side rounded and the other angulated and sharp or wedge-shaped ; umbones 
subcentral, depressed; lunule elliptical; denticles about 8—9 on each side; margins 
smooth. 
Length, ths of an inch; eaght, jth of an inch. 
Localities. Var. a, Highgate (Wetherell) ; var. 3, Barton (Edwards and S. Wood). 
‘his pretty little shell is by no means abundant. It strongly resembles Z. pygmaea, 
the existing British and Mediterranean species. 
There are two British Eocene shells that I think may be assigned to the French 
species; they differ a little in the number of denticles; the one from Highgate cor- 
responds closely with the description given by M. Deshayes; the other, from Barton, does 
not appear to have quite so many teeth in the hinge-line. They both differ from 
