Eocene Shells from Xijeri'a. 85 



Description of the Specimens, 

 l a m e l l i b r a n c h i a. 



Ostrea rarilamella ?, Desliayes. 



Ostrea rarilamella, Deshayes, Desc. Anim. sans Vert. 1861, vol. i. 

 pis. Ixxxi., Ixxxii., & vol. ii. p. 109 ; Archiac, in Tchihatcheft's ' Asie 

 Mineure,' Paleoutologie, 18)10-1869, pi. x. & pi. xi. lig. 1, p. 135; 

 Zittel, Palseontograpliica [Libyscheu Wiiste], 1883, vol. xxx. p. cxi. 



The specimen, referred doubtfully to this species, consists 

 of a fragment of an upper valve without, however, its hinge- 

 area. It shows great thickness of shell-structure ( = 13 milli- 

 metres), somewhat distant lamellge of growth, and a portion 

 of an extensive scar-impression. Beyond the scar-margin 

 the surface of the valve is rounded, smooth, slightly undu- 

 lating, and dipping towards the outer edge. In the absence 

 of more perfect material, a closer determination is scarcely 

 possible, although the general facies of the specimen com- 

 pares favourably with the figures and descriptions of this 

 species. 



Loc. Kalfu-Tamaskie. 



Collector. Colonel Elliot. 



Alectryonia cf. Martinsi, Archlac. 



Ostria orbicularis, J. de C. Sowerby, Trans. Geol. Soc. London, 1840, 



ser. 2, vol. v. pt. 2, pi. xxiv. fig. 8, non Linnteus. 

 Ostrea Martinsi, Archiac, Mem. Soc. Geol. France, 1850, s^r. 2, 



vol. iii. pt. 2, pi. xiii. fig. 25, p. 438. 



This form is represented by two fragments of a small, 

 depressed, suborbicular, and ostreiform shell having both its 

 valves plicated, and therefore a true Alectryonia. Its shape 

 and the bifurcation of the strong, prominent, and rounded 

 costse suggest affinities with A. ALvtinsi, from the Eocene 

 beds of Cutcli and Biarritz, though probably the valves of 

 that shell are rather more convex. 



Loc. Kalfu-Tamaskie. 



Collector. Colonel Elliot. 



Vulsella nigeriensis, sp. n. (PI. V. figs. 4, .5.) 



The collection contains a small subcircular form of Vul- 

 sella of greater horizontal than vertical measurement. The 

 umbones are nearly central, divergent, and acute, whereas the 

 sides of the valves are furnished with about nine convex 

 radial costae separated by shallow grooves, which proceed 



