PECTUNCULUS. 07 



Affinities. — This is similar to P. sublxvis, Sowerby, but is smaller, proportion- 

 ately less convex, and with less prominent umbones. 



Remarks. — Three specimens from the Lower Greerisand of Upware, which 

 were referred by Keeping {vide supra) to Pectunculus marullensis (and are 

 preserved in the Woodwardian Museum), seem to differ from that species in 

 having a subquadrate outline and more prominent umbones; the surface of the 

 shell in those specimens is worn, and it is consequently impossible to compare 

 satisfactorily the ornamentation. One example shows the hinge, but, unfortu- 

 nately, very indistinctly ; so far as I can see, the lateral teeth appear to be like 

 those of Cacullsea rather than Pectunculus. 



Types. — From the Neocomian of Marolles. 



Distribution,. — Ferruginous Sands (upper beds) of Shanklin. 



2. Upper Cretaceous Species. 



Pectuinculus suBLiEVis, Sou-erbij, 1824. Plate XIV, figs. 1 a — c, 2 a, b, 3 a — d, 



4 a — c, 5 a— c, 6, .7. 



1824. Pectunculus sublvEtis, J. de C. Sowerbi/. Min. Conch., vol. v, p. 112, 



pi. cccclxxii, fig. 4. 

 1850. — — A.d'Orbigny, Prodr.de Pal., vol. ii, p. 163 (partim). 



1S54. — J. Morris. Cat. Brit. Foss., ed. 2, p. 220. 



1868. — — A. Briartand F. L. Cornet. Descript. de la Meule 



de Bracquegnies (Mem. Cour. et Mem. des 

 Sav. etrangers, Acad. Boy. Belg. (vol. xxxiv), 

 p. 61, pi. v, figs. 21—23. 

 ? ? 1883. — — W. Keeping. Fobs., &c, Upware and Brickhill, 



p. 115, pi. v, fig. 9. 



Non 1837. — A. Ooldfuss. Petref. Germ., vol. ii, p. 160, pi. 



cxxvi, fig. 3. 



— 1813. — — H. B. Geinitz. Die Verstein. von Kieslingswalda, 



p. 14, pi. ii, figs. 19—21. 



— 1846. — — A. E. Renss. Die Verstein. der bohm. Kreide- 



format., pt. ii, p. 9, pi. xxxv, 

 figs. 10, 11. 



— 1S47. — J. Midler. Mon. Petr. der Aachen. Kreidef., 



pt. i, p. 17. 

 ? — 1883. — — 11. Schroder. Zeitschr. der Deutsch. geol. 



Gesellsch., vol. xxxiv, p. 274. 



Description. — Shell stout, convex, longer anteriorly than posteriorly, but 

 sometimes nearly equilateral; outline rounded or somewhat subquadrate; usually 

 a little longer than high. Antero-dorsal part compressed, with a rounded 



