2 CRETACEOUS LAMELLIBRANCHIA. 
Affinities. —D’Orbigny’ considered that this species was identical with his 
N. lingulata ;? but that form was founded on a cast, so that an exact comparison 
cannot be made. WN. lingulata, however, appears to be more pointed posteriorly 
and to taper more regularly than N. spathulata; it is also shorter anteriorly. 
N. spathulata is distinguished from N. solea (d’Orbieny) by its ornamentation 
and less elongate form. 
Remarks.—This appears to be a rare species; I have seen only six examples 
of it. Several of the specimens recorded by Gardner do not belong to this 
species, but to N. scapha (d’Orbigny) (see p. 4). The example from Speeton 
which he figures may be N. spathulata, but it is in the form of a cast, and the 
posterior part is not perfect. 
Types.—The type (Pl. I, fig. 1) is an internal mould, but shows indications of 
the ribbing; it comes from the Atherfield Clay, and is in the collection of the 
Geological Society of London (No. 2112). 
Distribution. — Crackers of Atherfield; Atherfield Clay of Atherfield ; 
? Speeton Clay of Speeton. 
Nocunana suprecurva (Phillips), 1829. Plate I, figs. 4a—e, 5a, b. 
1829. Nucuna suBrecurva, J. Phillips. Geol. Yorks., pt. 1, p. 122, pl. ii, 
fig. 11. 
1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 217. 
1866. — — EF. J. Pictet and G. Campiche. Foss. du Terr. 
Crét. des Envir. de Ste. Croix 
(Matér. Pal. Suisse, ser. 4), pt. 3, 
p. 401. 
1884. Lepa susrecurva, J. 8S. Gardner. Quart. Journ. Geol. Soc., vol. xl, 
p. 185, pl. v, figs. 24, 25. 
Non 1844. Nocuna suprecurva, dA. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, 
p- 170, pl. ecci, figs. 7—11. 
— 1850. Lepa susprecurva, d’Orbigny. Prod. de Pal., vol. ii, p. 186. 
— 1867. — — O. Fraas. Aus dem Orient, pt. i, p. 92. 
Description.—Shell inflated, elongate, inequilateral, the posterior part being 
much longer than the anterior; ventral margin gently curved; extremities 
rounded ; posterior part wedge-shaped ; anterior part narrow. Lunule depressed, 
not distinctly limited. Surface with concentric grooves and concentric striz. 
Measurements : (1) (2 
Length 5 : : 18 : : 1 
Height ‘ , , 10 : : 1 
Thickness . : 5 10 i 
1 *Prodr. de Pal.,’ vol. ii (1850), p. 117. 
* «Pal. Frang. Terr. Crét.,’ vol. iii (1844), p. 168, pl. ecciv, figs. 1—3. 
