VOL. XVII. (2) JURASSIC GERVILLIiE 24.5 



work. They are both labelled " Gervillia jornicata Lye, Sands, 

 Nailsworth," but the less well-preserved one, 25182, has, in 

 addition, the item " Handbook p. 121." It should have been 



"P- 25." 



It is proposed to select the better preserved specimen 

 [25183] as the standard of reference for the species. It consists 

 of a left valve (see pi. xxviii., fig. 3), very convex, having a 

 maximum diameter of 11 mm. The antero-ventral margin is 

 almost straight, and makes an angle of 45° with the hinge-line ; 

 the postero-dorsal margin is slightly concave. Two obscure, 

 but apparently circular, ligamentary pits can be made out on 

 the hinge behind the umbo. 



Only one right valve of the species has been examined. 

 This is on a specimen in Mr Richardson's collection from the 

 Cephalopod-Bed {moorei) at Coaley Wood, near Stroud ; it is 

 not well exhibited, but appears to be rather less convex than 

 the left valve. 



Gervillia oblonga Moore (Proc. Somerset. Archaeol. and 

 Nat. Hist. Soc, vol. xiii., 1867, p. 216, pi. 7, fig. 11) appears 

 from the figure to be closely related to G. fornicata. 



Records. — Variabilis-'Beds, Hartley Cottages well, Leckhampton Hill, 

 Cheltenham (L. R. — bed 5, Geol. Mag., 1910, p. 103) ; Variabilis-'Beds, Nails- 

 worth (idiotype locality) ; Cephalopod-Bed (moorei), Coaley Wood, near 

 Dursley (L. R. ; Proc. Cottesw. Nat. F. C, vol. xiii., pt. i, 1910, p. 115). 



GERVILLIA ISLIPENSIS Lycett. PL xxix., fig. 4. 



T.d. 1863. Lycett, Suppl. Monogr. MoU. Gt. Ool., p. 37. 



T.f. Ibid., tab. XL., fig. 35. 



T.l. " Stonesfield, Oxfordshire." 



H. " Stonesfield Slate." [Bathonian] 



^. [gracilis] 



Colin. Mus. Pract. Geol., Jermyn Street, London. [9179]- 



Remarks. — This fossil is poorly preserved and probably 

 came from one of the softer layers associated with the Stones- 

 field Slate-series. Lycett records it also from the Cornbrash of 

 Islip, Oxfordshire, but this specimen appears to be lost. 



This species is mentioned here because it should be found 

 in the basal Great Oolite of Gloucestershire and better preserved 

 specimens are desired. 



