Vol. 67.] KAINOZOIC MOLLUSCA FEOM CYRENAICA. 645 



narrow bands which give a regularly-imbricate surface to the 

 angulate ribs and sulcations. 



The specimen is very imperfect in the umbonal direction, and 

 only a fragment is preserved of the posterior auricle, no part of the 

 anterior wing being present ; a part of the ventral margin is also 

 fractured. 



Probably its nearest ally is a form described and figured by 

 D'Archiac as Pecten subojpercularis, from the Nummulitic deposits 

 of Bayonne : but in that shell the costse are far more numerous 

 and, moreover, fine longitudinal striations ornament the grooves, 

 which are not seen in the present specimen, otherwise the im- 

 bricating structure of the costae is very similar. 1 



Occurrence. — The specimen is associated with a pinkish lime- 

 stone full of Nummulites and Lithothamnion, the latter organism 

 showing out very plainly as smali white, more or less globular 

 masses. The matrix is entirely different from anything else in the 

 collection. 



Locality. — Above camp at Ain Sciahat. 



Vulsella sp. (PI. XL VI, fig. 7.) 



Description (left valve). — Specimen representing an elongate, 

 narrow valve, the posterior side of which shows a long marginal 

 curvature extending from the umbonal region ; the lateral margins 

 were probably more or less parallel, although the anterior one is 

 absent ; the surface is smooth and slightly convex. 



Dimensions : — Length = about 25 mm. ; height = 55 mm. 



Remarks. — This valve is very much fractured, but on account 

 of its lingulate contour it is possibly related to Vulsella crispata of 

 Paul Fischer, which Dr. Oppenheim identifies from the Nummulites- 

 intermedius Beds of Egypt, 2 and in lower horizons of the Eocene 

 of the same country. 



Occurrence. — It is attached to a compact cream-coloured 

 limestone, with a smaller example of the same genus in close 

 proximity showing concentric laminations. This matrix weathers 

 to a reddish colour, and contains Nummulites. 



Locality. — Base of cliffs, south-east of Merj. 



Vulsella cf. etmari Oppenheim. 



Vulsella eymari Oppenheim, Palaeontographica, 1903, vol. xxx, pt. 3, No. 1, 

 pi. vi, figs. 1-1 a & p. 74. 



Remarks. — External view of a left valve with an eroded 

 surface, and showing very obscure remains of concentric striation. 

 It is of oblong form with nearly parallel sides; an antero-dorsal 

 projection is present indicating an extension of the hinge-region, 



1 Mem. Soc. Geol. France, ser. 2, vol. iii, pt. 2 (1850) p. 436 & pi. xii, 

 figs. 19-19 a. 



2 Palasontographica, vol. xxx, pt. 3 (1903) No. 1, p. 68 & pi. iv,figs. 1-3 & 8, 

 pi. vi, figs. 12-13 & 15. 



