12 CRETACEOUS LAMELLIBRANCHIA. 
Family—NUCULIDA, Gray. 
Genus—Nocuta, Lamarck, 1799.' 
(‘Mém. Soe. Hist. Nat. Paris,’ p. 87.) 
1. Lower Cretaceous Species. 
Nucura puanata, Deshayes, 1842. Plate II, figs. 11-a, b, 12 a, b, 18, 14a, b, 15. 
1829. Nucuna ovata, J. Phillips (non Mantell). Geol. Yorks., pt. 1, pl. ii, 
1866. — 
fig. 10, p. 122. 
puanata, G. P. Deshayes. In A. Leymerie, Mém. Soc. Géol. de 
France, vol. v, p. 7, pl. ix, figs. 3, 4. 
optusa, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 163, 
pl. eee, figs. 1—5 (named WV. planata 
on pl. cece). 
impressa, F. J. Pictet and HE. Renevier. Foss. du Terr. Aptien 
de la Perte du Rhone, &e. (Matér. 
Pal. Suisse, ser. 1), p. 108, pl. xv, 
figs. 5, 6. 
PLANATA, F. J. Pictet and G. Campiche. Moll. Foss. du Terr. 
Crét. de Ste. Croix (Matér. Pal. 
Suisse, ser. 4), pt. 3, pp. 404, 417, 
pl. exxix, fig. 7. 
_ J.S. Gardner. Quart. Journ. Geol. Soc., vol. xl, p. 126, 
pl. v, figs. 1—4. 
Description.—Shell oval; short and angular posteriorly, high and rounded 
anteriorly; ventral margin considerably curved. Postero-dorsal margin nearly 
straight. Lunule elongate, bounded by a blunt carina. Shell depressed in front 
of the umbones. A faint ridge extends from the umbones anteriorly. Surface 
with lines of growth only. 
Measurements : 
Length 
Height . ‘ 
Thickness 
1—3 are from Speeton ; 
(1) (2) (3) (4) (5) 
OH 5 206 4 Deel Oso) el |G ean 
7 be Soya Algae O eoeellic’) aeeyeece) 
— .—. 65 .— . — 
4 and 5 from Atherfield. 
29 
39 
1 Tn the genus Nucula I regard the posterior dorsal area as the lunule, and the anterior dorsal as 
the escutcheon, since, except in position, they agree precisely with the lunule and escutcheon of other 
genera. In this matter I am in accord with Sylvanus Hanley (Mon. “ Nuculide,” in Sowerby’s 
«Thesaurus Conchyliorum,’ vol. iii [1866], p. 147, foot-note). 
