VOL. XVII. (2) 



APPENDIX 233 



APPENDIX 



NEW LAMELLIBRANCHS (GERVILLIA and PERNA) 

 FROM THE NE^RAN BEDS 



By E. TALBOT PARIS, P.C.S. 



[Plate XXVIL] 



During my work in connection with the revision of the 

 lamelUbranchs from the Lower and Middle Jurassic Rocks of 

 Britain, it has not been found possible to identify certain 

 species of GervilUa and Perna from the Nearan Beds of the 

 Chipping Norton District with any described forms. Hence 

 they are dealt with in this Appendix. 



PERVILLIA ENSTONENSIS sp. nov. PL XXVIL, fig. 2. 



Description (Left valve only,— Left valve moderately convex, with a 

 subovate outline. The hinge-margin is -73 of the length of the shell (measured 

 parallel to the hinge-line). Anterior and posterior extremities rounded. 



Remarks.— ¥xon\ GervilUa ovata (Sow.) this species differs 

 in being less elongate, and less curved. The posterior ex- 

 tremity is not so pointed, and the antero-ventral margin is 

 straighter than in that species. 



The form identified with GervilUa ovata (Sow.) by Morris 

 and Lycett (Monogr. MoUusca Gt. Ool., pt. H., p. 22, and tab. 

 n., figs. 12 and i2fl) appears to resemble this species. It has, 

 however, a more evenly rounded-ventral margin and a more 

 pointed posterior extremity. The hinge-margin also is slightly 

 concave, whereas in G. enstonensis it is straight. 



The holotype is from the Fossil-Bed (14) of the Bell-Inn 

 Quarry, Enstone, Oxfordshire. 



