ALBIAN FOSSILS DISCOVERED AT OKEFORD FITZPAINE. 87 



minute, concentric lines of growth ; the lateral costse, more 

 especially, have their intermediate grooves filled with a regular 

 series of closely-set oblique striations ; anterior ear obliquely 

 ribbed and faintly tubercled. 



The species differs from P. Robinaldinus in possessing fewer and 

 smoother costse ; from P. interstriatus it is distinguished by 

 bearing more numerous ribs, a more oblique ornamentation on. 

 the anterior auricle, and having a more orbicular contour ; from 

 P. Rothomagensis it is denned by its elevated and fewer costse 

 and by a less pronounced excavation beneath the anterior expansion. 



The Okeford Fitzpaine example is much smaller than D'Orbigny's 

 type, but corresponds exactly with the dimensions of a specimen 

 from Folkestone in the British Museum. 



Dimensions Height = 25"),, 



[Millimetres. 



Length = 20J 



RANGE OF SPECIES. Albian to Cenomanian. 



LOCALITIES. Isle of "Wight (Ventnor), Folkestone, Devon, 

 Warminster ; in the N.W. of France, such as Coudrecieux 

 (Sarthe), Villers (Calvados), St. Jouin and La Hove ; and in the 

 Ardennes, Meuse, and Aube districts of France. 



GERVILLIA FORBESIANA, Orbigny. 



Gervillia solenoides, J. de C. Sowerby : Mineral Conchology, 

 1826, Vol. 6, PI. 510, figs. 1-4, p. H non Defrance. 



Gervillia Forbesiana, Orbigny : Paleontologie Francaise, Terrains 

 Cretaces, Lamellibranchia, 1843, PI. 396, figs. 5-6, p. 486. 



This is a very elongate, compressed, arched, narrow and thin, 

 tested species. The hinge line is short and furnished with small 

 aliform expansions, anterior one diminutive ; ornamentation 

 consisting of lines of growth. One of the two specimens belonging 

 to this species is in fairly good condition, though without any 

 ornamentation ; its valves, embedded in matrix, are united at the 

 hinge, but separated posteriorly. 



Dimensions Height =. 7 | 



T ., nA ( Millimetres. 

 Length = 34 ) 



