CUCULLAA. 55 
sidered that the form which is abundant at Donnington! was distinct. After a 
_ eareful comparison of a larger series of the latter with the type-specimen I am 
unable to see any real difference. The figure given by Keeping is not quite 
accurate in outline, and is drawn from a gutta-percha cast; the mould itself is 
not perfect at the anterior and ventral margins, and near the umbo a portion of 
the shell remains in it. 
Types.—In the Woodwardian Museum, Cambridge, from Upware. 
Distribution.—Lower Greensand (black grit nodules) of Upware. Claxby 
Ironstone (zone of Bel. lateralis) of Benniworth Haven, near Donnington. 
Spilsby Sandstone of Donnington. 
Cucutnma (Dickanoponra ?) oBLiqua (Keeping), 1883. Plate XI, figs. 3 a—e, 4. 
1883. ProruncuLus opiiguus, W. Keeping. Foss., &c., Neoc. Upware and Brick- 
hill, p. 116, pl. vi, fig. 1. 
Non 1826. —_ _— Defrance. Dict. Sci. Nat., vol. xxxix, p. 224. 
— 1883. — obxieua, J. Lea. Contrib. Geol., p. 78, pl. iii, fig. 57. 
— 18385. — oBLiquus, G. Miinster. Neues Jahrb. fiir Min., &c., p. 488. 
— 1843. — — LI. Reeve. Conch. Icon., vol. i, pl. vi, fig. 33. 
Description.—Shell stout, ovate-oblong, inequilateral, moderately convex but 
flattened centrally. Anterior border rounded, ventral slightly curved, posterior 
oblique and slightly curved—forming with the ventral a blunt angle. Shell com- 
pressed dorsal to a line from the umbo to the postero-ventral angle. Umbones 
small, rather close together. Hinge-line short. Hinge-area narrow, with many 
ligament-grooves. Surface of shell with fine radial striz and a few fairly well- 
marked lines of growth. Central teeth few, small; the laterals (two or three) 
long, the first parallel to the hinge-margin, but the last curving ventrally. 
Measurements : 
(1) (2) 
: Length. : : ; : eG : 20 mm. 
Height. : : : : ey als eee DVemouss 
Thickness : : oe LO : ao “i 
Affinities —This form was referred by Keeping to Pectunculus, but the character 
of the teeth show that it cannot be placed in that genus. The concluding 
remark of the author mentioned (“It approaches nearest to some Jurassic species 
from the Great Oohte and Coral Rag”’) seems to show that he was really thinking 
of Cucullea rather than Pectunculus. The fact that the lateral teeth (or some of 
1 Erroneously spelt Doddington by Keeping (‘ Foss. Upware,’ &e.), p. 158. 
