246 PROCEEDINGS COTTESWOLD CLUB 191 1 



GERVILLIA L^VIS James Buckman. PI. xxviii., figs. 2a, b. 



T.d. 1844. " An Outline of the Geology of Cheltenham," 2nd ed., 



Appendix, p. 98. 

 T.f. Ibid., tab. 10, fig. 8. 

 T.l. " Foot of Battledown Hill, Hewlett's Road [Cheltenham, 



Gloucestershire] . ' ' 

 H. " [Lower] Lias." [Pliensbachian] 

 ^. [striati] 



Colin. Mus. Pract. Geol., Jermyn Street London. [3683]. 

 1904. Gervillia IcBvis J. Buckman, L. Richardson, " Handbook to 



the Geology of Cheltenham," pp. 45 and 221, pi. XV., fig. 4. 



Type-description.^" Hinge line a little more than one-third the length 

 of the shell, teeth few, but narrower than in the preceding [Gervillia crassa], 

 shell slightly curved, very smooth and thin, anterior extremity rather pointed." 



Remarks. — The holotype is preserved in the Museum of 

 Practical Geology [3683], and is from the Striatum-^ediS of the 

 Lower Lias at Battledown, Cheltenham. 



As shown by the measurements given below, the length 

 of the hinge-hne relative to the length of the shell is -62 or -69, 

 (according as the " length " is measured parallel to the hinge- 

 line or diagonally from the anterior to the posterior end) and 

 not " a little more than one third " as stated by Buckman. 

 The " teeth " referred to in the protolog are the ligamentary 

 grooves. 



At certain localities (given below) there occurs an abun- 

 dance of a small form of Gervillia IcBvis. These may be either 

 immature examples of the species or a dwarf variety ; there 

 is not yet sufficient evidence to justify a decision. Typical 

 examples of G. IcBvis occur at the same horizon, but have not 

 been found associated with the small form. 



The following are the measurements of four specimens: — 



Specimen Length Height Diameter Hinge-hne 



29-5 

 29 



23-5 



19 



Specimen No. 2 is the holotype ; Nos. i and 3 are topo- 

 types ; and No. 4 is a specimen from the Capricornus-Beds at 

 Pilford, Cheltenham. Six of the small forms mentioned above 



I 



