222 CRETACEOUS LAMELLIBRANCHIA. 
PANOPEA SPILSBIENSIS, sp. nov. Plate XXXVIII, fig. 2a, b. 
Description.—Shell elongate-oval, convex, not very inequilateral. Posterior 
part more compressed and not so high as the median and anterior parts. Anterior 
margin rounded; ventral margin slightly curved, not quite parallel to the long 
dorsal margin. Umbones broad, incurved, at about six-fifteenths of the entire 
length from the anterior end. Pallial sinus large, deep, and rounded. Surface of 
shell nearly smooth. 
Remarks.—Only a few internal casts with small portions of the shell preserved 
have been obtained, but they seem to differ considerably from other species and 
are provisionally referred to the genus Panopea. 
Distribution.—Spilsby Sandstone (zone of Belemnites lateralis) of Donnington. 
Panopna GuRGITIS (Brongniart), 1822. Plate XXXV, figs. 9—14; Plate XXXVI, 
figs. 1—8. 
1822. Lurrarra cureitis, A. Brongniart, in Cuvier. Ossemens Foss., vol. ii, pt. 2, 
pp. 333, 615, pl. ix, fig. 15. 
1823. Mya pricara, J. de C. Sowerby. Min. Conch., vol. v, p. 20, pl. eccexix, fig. 3. 
1835. Panopma piicata, Sowerby. Ibid., vol. vi, Systemat. Index, p. 241. 
1841, —_ _- F. A. Romer. Die Verstein. d. nord - deutsch. 
Kreidegeb., p. 75, pl. ix, fig. 25. 
1842. PHoLADOMYA NEocomiIENnsIS, A. Leymerie. Mém. Soc. géol. de France, ser. 2, 
vol. v, p. 3, pl. iii, fig. 4. 
— - Prevosti, Deshayes in Leymerie. Ibid., p. 3, pl. ii, fig. 7. 
1845. PANopma NEOCOMIENSIS, A. dOrbigny. Pal. Franc. Terr. Crét., vol. i, 
p. 329, pl. cccliu, figs. 3—8. 
Prevosti, dOrbigny. Ibid., p. 334, pl. ecelvi, figs. 3, 4. 
NEOCOMIENSIS, H. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 238. 
~— — puicaTa, Morbes. Ibid., p. 238. 
—  Myopsis neocomigensis, L. Agassiz. Etudes crit. Moll. Foss., Myes, p. 257, 
pl. xxxi, figs. 5—10. 
_ — UNIOIDES, Agassiz. Ibid., p. 258, pl. xxxi, figs. 11, 12. 
1850. Panopma NEocomigENSIS, A. d’Orbigny. Prodr. de Pal., vol. ii, pp. 73, 117. 
—- — Prevosrit, d’ Orbigny. Ibid., pp. 105, 117. 
1852. -—- pLicata, F, J. Pictet and W. Roux. Moll. Foss. Grés verts de 
Geneve, p. 399, pl. xxviii, fig. 2. 
= — Ruopant, Pictet and Roux. Ibid., p. 400, pl. xxviii, fig. 3. 
1854. MyacirEes NEocomIENSIS, J. Morris. Cat. Brit. Foss., ed. 2, p. 213. 
1855. Panopma —- F. J. Pictet and E. Renevier. Foss. Terr. Aptien 
(Matér. Pal. Suisse, ser. 1), pp. 56, 175, pl. vi, 
fies. 2, 3. 
—- — piicata, Pictet and Renevier. Ibid., p. 57, pl. vi, figs. 4, 5. 
