LIMA. 31 



Renin fliS. — The cliiof cliavucter in which Liittit Juningtloiiru.sis differs from 

 L. parallela seems to be in the possession of well-marked ribs over the whole of 

 the anterior area. It also differs from the majority of examples of L. parallda in 

 that the ribs only decrease in size to a very small extent in passing from the 

 anterior to the posterior part of the shell; and further, the shell is less inequilateral 

 than is usual in L. parallela. 



I am inclined to regard Lima farrliigdonensis as not more than a variety of 

 L. paraUcla, but without better material it is impossible to express a confident 

 opinion. Almost all the specimens seen are in the condition of intei-nal casts in a 

 brownish ferruginous sandstone. 



Type. — The figure given by Sharpe is taken from a gutta-percha cast of an 

 external mould. It was obtained from Seende and is preserved in the Museum of 

 the Geological Society. 



Bidribution. — Lower Grcensand of Seende and Faringdon. 



Lima (M.vntelt.um) uaultina, nom. nov. Plate V, figs. IG — 2(>. 



? 1827. Plagiobtoma elongata, /. Jc C Smvcrhij. Miu. Couch., vol. vi, ji. 113, 



1)1. dlix, fig. 2 (upper figure ouly). 

 1847. Lima paeallela, A. d'Orhitjuy. Pal. Frauc. Terr. Crt't., vol. iii. p. 539, 



pi. ccccxvi, figs. 11 — 14. 

 1850. — — d'Orhlijiiij. Prodi-, de Pal, vol. ii, p. 138. 



1855. — — G. ColteiiH. Moll. Foss. de ITouue, p. 101. 



1854. — elongata, /. Murris. Cat. Brit. Foss., ed. 2, p. 171 (jjaiiim). 

 1875. — — A. J. Jukes-Browne. Quart. Jouru. Geol. Soc., vol. xxxi, 



p. 2;i(i. 

 1897. — parallela, R. B. Ncwtun. Proc. Dorset Nat. Hist, aud Autiij. Field 



Club, vol. xvii, p. 88, pi. iii, fig. 11. 

 IPOO. — — E. T. Newton aud .1. J. Jukes-Browne. Cret. Eocks of 



Britain, vol. i, p. 449. 



Nou 1850. Plagiostuma parallelus. J. de C. Suwerbij iu F. Duoii. Geol. Sussex, 



p. 35t) (p. 386, ed. 2), pi. xxviii, 

 fig. 16 (=1/. elongata, Sowerby). 



Description. — Shell rather compressed, sulj-cpiadrangidar or nearly oblong, very 

 oblique, nuich longer than high, rounded posteriorly ; antero-dorsal margin long 

 and nearly straight, almost parallel with the postero-ventral margin. Apical angle 

 about 100°. Umbones pointed, close together. Ears of moderate size, the anterior 

 larger than the posterior. Anterior area lai-ge, slightly concave dorsally, orna- 

 mented with fine radial ribs. 



Ornamentation consists of 18 to '20 main rilis witli a few smaller ribs pos- 

 teriorly. The ribs are strong, witli sharp summits, but become somewhat 



