90 ALBIAN FOSSILS DISCOVERED Al OlJEFORD FITZPAINE. 



Mytilus sulsimplex, Pictet and Renevier : Desc. Foss. Aptien 

 Perte du Rhone et St. Croix, 1858, PI. 16, fig. 3, p. 114. 



In my first paper I determined this shell as being allied to 

 M. subsimplex, but a further study of the specimen inclines me now 

 to regard it as a true form of Leymerie's species, as emended by 

 d'Orbigny, who made it to include the arched variety, as well 

 as those of straighter contour. The Okeford Fitzpaine example 

 shows an external aspect, with the valves open. It is strongly 

 curved or arched, narrow, elongate, and smooth ; the valves are 

 attached by a long, linear hinge ; anterior extremities are obtusely 

 pointed, posterior ends being broad and rounded. Some indistinct 

 traces of concentric growth lines are observable in places. This is 

 a very graceful and elegant shell, and appears to differ from all 

 other species, not only in these details, but also in its elongate form 

 and generally smooth appearance. 



Dimensions Length = 57 



, Millimetres. 

 Width (max.) = 17 



RANGE OF SPECIES Neocomian to Albian. 

 LOCALITIES. Atherfield, Black Ven, Perte du Rhone, Savoy, 

 Geneva (environs), Haute-Marne, Yonne, &c. 



NUCULA PECTINATA, J. Sowerby, 



Nucula pectinata, J. Sowerby : Mineral Conchology, 1818, Vol. 2, 

 Plate 192, figs. 6-7, p. 209. Mantell : Geology of Sussex, 1822, 

 Plate 19. figs. 5-6-9, p. 94. Orbigny : Paleontologie Franyaise, Ter- 

 rains Cretaces, Lamellibranchia, 1843, Plate 303, figs. 8-14, p. 177. 



This is one of the most characteristic of the Gault shells. It is 

 transversely elliptical, elongate, and convex ; truncated and 

 angulate anteriorly, but produced and subangulate in rear ; lunule 

 cordate and much excavated ; surface ornamented with radiating 

 ribs, crossed by fine, closely-set concentric stria3 ; inner edges 

 crenulated. The wide cordate lunule and the details of the 

 ornamentation distinguish this from all other species of Nucula. 



There are two fairly good specimens in the collection showing 

 most of the above characters, besides some obscure remains of a 



