ALBIAN FOSSILS DISCOVERED AT OKEFORD FITZPAINE. 93 



appearing to represent a much coarser shell without the tubercled: 

 surface, and having radial costae, which are curved and fewer in 

 number. The great breadth of the valves, however, agrees very 

 well with our specimen. 



Such differences as are here alluded to led Pictet and Roux to 

 question d'Orbigny's determination, and it is more than likely that 

 if the types could be consulted they might be separated with 

 advantage. It is worthy of mention that the Barremian and Aptian 

 species, P. Martini of Forbes (Quart. Journ. Geol. Soc., 1845, Vol. 1, 

 PI. 2, fig. 3, p. 238) appears to be so closely related to P. Fdbrina 

 of Orbigny that both forms may subsequently require to be merged 

 under the former name. The specimens from Black Ven, referred 

 to this species, are in the same condition of preservation. 

 Dimensions of specimen \ Height *= 27 \ 



with both valves > Length = 57 > Millimetres, 

 attached ) Breadth = 39 ' 



RANGE OF SPECIES. Albian. 



LOCALITIES. Black Ven and Folkestone ; d'Ervy and Perte du 

 Rhone on the Continent. 



PLEUROMYA PLICATA, J. de C. Sowerby. 

 [For synonomy see p. 71.] 



Two specimens of this form are attached to the same slab of clay, 

 showing extended valves with the regular curved plicae, the 

 incurved umbonal area and posterior truncation being well repre- 

 sented. 



SOLEN DUPINIANUS, Orbigny. 



Solen Dupinianus, Orbigny : Paleontologie Francaise, Terrains 

 Oetaces, Lamellibranchia, 1843, PI. 350. figs. 3-4, p. 320. De 

 Ranee : Geological Magazine, 1874, p. 252. 



A single left valve is all that was obtained of this extremely rare 

 species at Okeford Fitzpaine. A small part of the posterior end is 

 absent, otherwise the specimen is in fairly good condition. 



It is elongate, compressed, slightly narrower anteriorly, and 

 vertically truncated in rear. The dorsal and ventral margins are 



