10 CRETACEOUS LAMELLIBRANCHIA. 
Noucunana Visrayeana (d’Orbigny), 1844. Plate IT, figs. 4a—c, 5a, b, 6—9. 
1844. Nucuta Vrprayeana, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. in, 
p- 172, pl. ecci, figs. 12—14. 
1850. Lepa Vrsrayeana, A. d’Orbigny. Prodr. de Pal., vol. 11, p. 186. 
1852. Nucuna Visrayeana, FE. J. Pictet and W. Roux. Moll. foss. Grés vert 
de Genéve, p. 471, pl. xxxix, fig. 2. 
1861. — SUBELLIPTICA, H. G. Seeley. Ann. Mag. Nat. Hist., ser. 3, 
vol. vii, p. 120, pl. vi, fig. 4. 
1861. _ RHOMBOIDEA, Seeley. Ibid., p. 120, pl. vi, fig. 5. 
1866. Lupa Vrsraveana, F, J. Pictet and G. Campiche. Foss. Terr. Crét. de 
Ste. Croix (Matér. Pal. Suisse, ser. 4), 
pt. 8, pp. 399, 401, pl. exxix, figs. 5, 6. 
1884. — _ J. S. Gardner. Quart. Journ. Geol. Soe., vol. xl, 
p. 187, pl. iii, figs. 17, 18, 25; pl. iv, figs. 
26, 27. 
Description.—Shell oval, rounded, convex centrally, compressed at the extre- 
mities, nearly equilateral, but with the posterior part slightly longer than the 
anterior ; extremities rounded. Ventral margin considerably curved at the median 
part. Antero-dorsal and postero-dorsal margins with a considerable ventral 
slope from the umbo. Umbones not prominent. Lunule indistinct. Escutcheon 
lanceolate. Surface smooth. Margins smooth. Anterior adductor impression 
somewhat quadrate; the posterior a little smaller and more rounded. Pallial 
line slightly sinuous posteriorly. 
Measurements : 
(1) (2) (3) (4) (5) (6) (7) 
Mbeya ey Mise Be dls NY 5 Ee Oe 8) 
0 
ileal IGG I ech So FS) 
Minton es i (DG 
Affinities.—See under N. Seeleyi, Gardner (p. 5). 
Remarks.—As was pointed out by Gardner, Seeley’s N. subelliptica (PI. II, 
fig. 9), and N. rhomboidea from the Cambridge Greensand, are simply internal 
casts of N. Vibrayeana. 
Types.—I was unable to find the type in the d’Orbigny Collection at the 
Museum of Natural History, Paris. The types of N. subelliptica, Seeley, and 
N. rhomboidea, Seeley, are in the Woodwardian Museum, Cambridge. The 
examples figured by Gardner are in the British Museum. 
Distribution. —Lower Gault (zones y, vii, and viii) of Folkestone ; Cambridge 
Greensand (derived). 
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