56 CRETACEOUS LAMELLIBRANCHIA. 
them) curve ventrally, and also the form of the shell, seem to connect this species 
with C. donningtonensis, Keeping (vide supra, p. 54). 
Remari:s.—The specific name given by Keeping is preoccupied as shown 
above, but, since the species is now removed from Pectunculus, the specific name 
can be retained. 
Types.—The only specimens seen are the types (three in number) from Upware, 
preserved in the Woodwardian Museum, Cambridge. 
Distribution.—Lower Greensand of Upware. 
2. Upper Cretaceous Species. 
CucuLLma venusta, Nyst, 1848. Plate XI, figs. 5 a—c, 6a, b, 7a, b. 
1836. CucuLtnma Formosa, J. de C. Sowerby. Trans. Geol. Soe., ser. 2, vol. iv, 
p. 342, pl. xvii, fig. 7. 
1848. Arca (CucunL®a) venusta, H. P. Nyst. Tableau des Espéces vivant et 
foss. des Arcacées (Mém. Acad. Roy. Belg., 
vol. xxil), p. 76 (nom. mut.). 
1850. — suBrorMosa, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 164 (nom. mut.). 
1854. CucuLttma Formosa, J. Morris. Cat. Brit. Foss., ed. 2, p. 197. 
1866. Arca (Cucunnma) Formosa, F. J. Pictet and G. Campiche. Foss, Terr. Creét. 
Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. ii, p. 473. 
21868. — susrormosa, A. Briart and F. L. Cornet. Descript. de la Meule de 
Bracquegnies (Mém. Cour. et des Sav. étrangers, Acad. 
Roy. Belg., vol. xxxiv), p. 54, pl. v, figs. 11, 12. 
1871. — Formosa, F. Stoliczka. Palwont. Indica, Cret. Fauna 8S. India, 
vol. ill, p. 843 (? ZLrigonoarca). 
Non 1833. Cucutima Formosa, G. B. Sowerby. Proc. Zool. Soe., pt.1, p.20. (Figured 
Reeve, Conch. Icon.. vol. 11, 1844, pl. ii, fig. 10.) 
Measurements : 
(1) (2) (3) 
Length , ; : > 8 : 7 é 4 min. 
Height. 5 3 sien 020 : 5b : Oe ast 
Remarls.—I have seen only five specimens of this form—three in the Bristol 
Museum and two belongmg to Mr. Meyer. The shell is not well preserved in any 
case. In form, and the character of the concentric ornamentation, it is near to 
QO. Fittoni (see p. 52), but all five specimens are much smaller. 
C. venusta appears to differ from C. Mittoni in beg more convex; in having 
the ventral margin less curved posteriorly—so that the postero-ventral angle is 
