VOL. XVII. (2) JURASSIC GERVILLI^ 249 



GERVILLIA PR^LONGA Lycett. 



T.d. 1857. " The Cotteswold Hills," p. 127. 



T.f. Ibid., pi. VI., fig. 6. 



T.l. " Rodborough Hill, [Stroud, Gloucestershire]." 



H. " The Spinosa-Stage of the Inferior Oolite in the Gryphite-Grit 



[Lower Trigonia-Grit]." [Bajocian] 

 'i. [discitce] 

 Colin. Mus. Pract. GeoL, Jermyn Street, London. [8864]. 



Remarks. — This species is closely allied to Gervillia sub- 

 cylindrica Morris and Lycett and to G. acuta Sowerby. From 

 the former it is distinguished by the greater curvature of the 

 shell — G. subcylindrica being almost straight. G. acuta appears 

 never to attain the size of G. prcelonga, has a relatively shorter 

 hinge-line, is higher, and more pointed at its posterior extremity. 



Collectors in the Cotteswolds have often referred the right 

 valve of this species to Gervillia acuta Sowerby, to which it 

 bears a strong resemblance. 



The specimen figured by Lycett is a left valve from the 

 Lower Trigonia-GviV of Rodborough Hill, near Stroud. It 

 has the following dimensions : — length, ca. 146 mm. ; height 

 ca. 38 mm. ; hinge-line, ca. 83 mm. 



Records. — Clypeus-Grit {schlasnbachi), Rolling Bank Quarry, Cleeve Hill, 

 jiear Cheltenham ; Notgrove Freestone (mitchelliis), Leckhampton ; Witchellia- 

 Grit {witchellice). Cold Comfort, near Cheltenham ; Buckmani-Grit {post- 

 discitcB), Cleeve Hill, near Cheltenham ; Tufifiey's Quarry, near Crickley Hill, 

 and Charlton Common, near Cheltenham ; Lower Trigonia-Grit (discita), 

 Rodborough Hill, near Stroud ; Leckhampton Hill, Charlton Common, and 

 Wistley Hill, near Cheltenham. 



GERVILLIA SUBCYLINDRICA Morris and Lycett 



T.d. 1853. Mongr. MoU. Gt. Ool., pt. II, p. 21. Pal. Soc. 



T.f. Ibid., tab. III., figs. 13, 13a and b. — " Gervillia subcylindrica 



? var. of Gervillia acuta Sow." 

 T.l. " Minchinhampton Common, where it occurs somewhat rarely 



in the 

 H. " planking [Great Oolite] " [Bathonian] 

 'J. [? maxillatce] 

 Colin. Mus. Pract. GeoL, Jermyn Street, London. [9181, 9182] 



I Matrix identified by Mr Richardson 



