U EOCENE MOLLUSCA. 



contemporaneous deposits in England. The shell described by Mr. Sowerby 

 ( c Min. Con.,' vol. iv, p. 89 bis, t. 366), as B. costettatus, is an Achatina. Two of 

 the French Eocene species have been found, mixed with marine remains, in the 

 Faluns of Touraine ; but, as yet, no species has been found below the Eocene 

 formations. 



No. 23. Bulimus ellipticus. Sowerby. Tab. XI, fig. 2 a—f. 



Bulimus ellipticus. Sowerby. 1822. Min. Con., vol. iv, p. 46, t, 337. 



— tenuistriatus. G. Sowerby, jun., 1846. Lond. Geol. Journal, vol. i, p. 20. 



B. testa sinistrorsd, ovali, elongatd ; apice obtuso : anfractibus plano-convexis, svperne 

 sub-canaliculatis; transversim lineatis; lineis obliquis, irregularibus, plus minus-ve numerosis ; 

 aperturd sub -aur if or mi, peristomate simplici, margine columellari rejtexo. 



A sinistral, cylindrically -conical shell, with an apex more or less obtuse in different 

 individuals ; the whorls are slightly convex, depressed at the upper margin so as to 

 form an obscure channel running parallel with the suture, and covered with numerous 

 transverse raised lines, which are rounded, oblique, and vary considerably in number, 

 frequently in the same specimen. The aperture is oblong and ovate ; the sharp outer 

 margin is slightly reflected where it joins the columella, and is frequently thickened as 

 it spreads over the body-whorl. 



Fig. 2/ is taken from a specimen belonging to Mr. Wetherell, found in the exca- 

 vations in the London Clay at Primrose Hill for the London and Birmingham Railway. 

 The lineation of this fragment is fainter and more crowded, and the whorls appear to 

 be more angular at the base than in B. ellipticus ; these distinctions induced Mr. 

 G. Sowerby to refer the shell to a distinct species. The faintness of the transverse 

 lines is, however, due to the worn state of the shell, which has apparently lost the 

 outer layer; and their number is a character too uncertain to be relied upon. The 

 specimen represented by fig. 2 a, from Mr. D'Urban's collection, shows on one side 

 of the penultimate whorl, lines nearly as crowded as those on the Highgate specimen, 

 while those on the opposite side of the same whorl are moderately distant; and 

 I have in my own collection a specimen, beautifully preserved, in which the same 

 discrepancy occurs. The angularity of the whorls is a character frequently found 

 in shells in an early stage of their growth, and I have several young shells of this 

 species, in which the whorls present a clearly defined angle running round the basal 

 periphery. On these grounds I have referred the specimen in question to the present 

 species. 



A form occurs at Binsted, near Ryde, in which the whorls are flatter than in 

 ordinary specimens, and sub-turrited ; in other respects it agrees with this shell, of 

 which, therefore, I consider it to be only a variety. 



