SAINT HELENA. 545 



The Bidimus which is referred by Reeve to the helena of 

 Quoy is certainly distinct from the present one ; and if it be 

 truly found at St. Helena at all (concerning which I think that 

 we require further evidence), I do not see, judging from the 

 figure, why it might not represent a recent, or nearly-recent, 

 state of the B. Blofeldi ; in which case it might perhaps answer 

 to the species which is said by Forbes to have been found by 

 Mr. Alexander, many years ago, in a living condition, and 

 feeding on the foliage of the cabbage-trees, on the highest part 

 of the great central ridge. 



Bulimus fossilis. 



T. prsecedenti fere similis, et forsan vix specifice distincta* 

 Differt testa paululum minore subsolidiore, spira subbreviore, 

 anfractibus circa 5 (nee 6) composite, anfractibus subbrevioribus, 

 ultimo vix magis inflato-rotundato, apertura paululum minore 

 angustiore, margine columellari sensim latius dilatato magisque 

 rotundato {i. e. minus verticaliter recto). — Diam. maj. 5 ; long. 

 lh Un. 



Cochlogena fossilis, Soiv., in Darwin's Vole. Isl., Append. 



156 (1844) 

 Bulimus fossilis, Forbes, Joiirn. Oeol. Soc. Lond. viii. 199. 



t. 5. f. 4 (1852) 

 „ „ Pfeiff., Mon. Hel. iv. 506 (1859) 



„ „ Melliss, St. Hel. 122 (1875) 



Habitat in solo insulse conchylifero ; semi fossilis. 



Judging from the variability of the B. helena, which is apt 

 to take a slightly different outline according to the exact spot, 

 or ridge, on which it is found, I feel extremely doubtful whether 

 the present Bulimus is anything more than a somewhat unim- 

 portant modification of that species which has become a little 

 more solid through a longer process of semifossilization, and in 

 which, consequently, the spiral lines are well-nigh effaced. It 

 is true that it is a trifle shorter and more ventricose, and its apex 

 seems to have a whorl (or perhaps only half a whorl) less, but in 

 the genus Bidimus such characters as these are hardly worth 

 alluding to ; nevertheless since the aperture also is just appre- 

 ciably smaller, and the columella is not quite so straightened, I 

 will not suppress it as a species, though I must frankly admit 

 that I have very little faith in its claims for separation. 



I possess an example of the B. fossilis which was taken by 

 Mr. P. Whitehead on the ridge between Flagstaff Hill and 

 Sugarloaf, and which accords precisely with the figure as given 

 by Forbes ; but the original type from which Sowerby's diag- 

 nosis was drawn out was met with, I believe, in the cutting of 



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