PHOLADOMYA. 245 
numerous, fine, regular ribs parallel with the posterior margin ; on the remainder 
of the shell similar ribs, but running in a radial direction, occur. 
Measurements : 
(1) (2) (3) (4) 
Length . : 37 33 ‘ 30 : 20 mn. 
Height . . 2S : 22, P 21 : Are 
Thickness. . 15 14 — 10 
6 
(1) Chalk Marl, Chard. 
(2, 4) Chloritic Marl, Devizes. 
(3) Chalk Marl, Ventnor. 
Affinities.—In this species the shell is more elongate and less convex, the carina 
more prominent, and the postero-dorsal area larger than in 7’. rotwidata (p. 241). 
T'. cariifera is closely allied to T. elegans (VOrbigny),! from the Cenomanian of 
St. Sauveur, but is less elongate. 7’. Germart (Geinitz)’? from the Senonian, is 
regarded by Brauns’ as a synonym of 17. carinifera ; but without seeing specimens 
of the former it is difficult to express an opinion of its relationship. 
Remarks.—The specimens vary considerably in the proportion of length to 
height, but im some cases the differences are probably due partly to crushing. 
The shell itself is seldom preserved. 
T'ype.—The type came from the Cenomanian of Dowlands (South Devon) and 
was originally in the collection of Sir H.'T. De la Beche, but cannot now be 
found. 
Distribution.—Chloritic Marl of Devizes and Maiden Bradley. Chalk Marl of 
Ventnor, Evershot, and Chard. 
Family—PHOLADOMYIDA, Gray. 
Genus—Puotavomya, G. B. Sowerly, 1825. 
(‘Genera Rec. and Foss. Shells,’ no. xix, pl. xxxvii.) 
PuonapoMya CorNnuELtana (d’Orbigny), 1844. Plate XLI, figs. 2a, b, 3. 
1844. Carpium CornueLianum, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. i, 
p. 28, pl. eclvi, figs. 1, 2. 
1845. — — EH. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 243. 
1850. PHoLtapomya Cornuewiana, A. d’Orbigny. Prodr. de Pal,, vol. ii, p. 117. 
1854. Carprum Cornvurianum, J. Morris. Cat. Brit. Foss., ed. 2, p. 192. 
1 ‘Pal. Frane. Meas Crét.,’ vol. i (1845), p. 386, pl. ceelxxiii, figs. 3—o: 
‘ Quadersandst. oder Kreidegeb. in Deutschland ’ (1850), p. 150, pl. x, figs. 9—11. 
3 *Senon. Mergel d. Salzberges,’ Zeitschr. f. d. gesammt. Naturwiss., vol. xlvi (1876), p. 359, pl. x, 
figs. 18, 19. 
2 
