472 TESTACEA ATLANTXCA. 



Canarian claims. If MM. Webb and Berthelot really discovered 

 it in the archipelago, why did they not tell us where ? Whereas 

 the certain fact that Webb carelessly introduced many land- 

 slide Into his fauna on evidence which was altogether insuffi- 

 cient, and which have since been ascertained to belong to other 

 countries, would go far to create a suspicion, under the circum- 

 stances, that the C. elegans (a broken example of which, from 

 the so-called ' Canarian ' material of Webb, is in the d'Orbignyan 

 collection at the British Museum) may perhaps, in reality, have 

 been one of the number. Nevertheless as this is not now ac- 

 tually demonstrable, and the species is on record (however 

 vaguely) as Canarian, I think perhaps that we should hardly be 

 justified in refusing it admission into the list. 



Apart from all other characters, the C. elegans may at once 

 be known from every phasis of the canariense by its suture 

 being not only single (or unlacerated) but also more deeply 

 impressed (causing the volutions to be more convex), and by its 

 aperture being more decidedly circular. 



Cyclostoma lsevigatum. 



Cyck stoma laevigatum, W. et B., Ann. ties Sc. Nat. 28. syn. 



322 (1833) 

 „ canariense, var., d'Orb., in W. et B. Hist. 76 



(1839) 

 „ kevigatum, pars, Pfeiff., Mon. Pneura. i. 229 



(1852) 

 Cyclostomus lsevigatus, Mouss., Faun. Mai. des Can. 143 



(1872) 



Habitat Gomeram ; in saxosis declivibus, et recens et semi- 

 fossilis, occurrens. 



As stated under the C. canariense, it is with considerable 

 reluctance, and only out of deference to the opinion of previous 

 monographers, that I record the present Cyclostoma as speci- 

 fically distinct ; nevertheless since, in addition to its peculiarity 

 of sculpture (the spiral costas being almost or even entirely 

 obsolete except towards the apex of the shell, whilst the fine 

 longitudinal hair-like lines are evenly and uninterruptedly de- 

 veloped), it possesses also a slightly more ovate, or less^ rounded, 

 outline, I have the less compunction about treating it practi- 

 cally as a separate species, even whilst feeling it more probable 

 that it is, in reality, but an insular phasis peculiar to Gomera 

 of the extremely unstable C. canariense. But I would remark 

 that one of the chief characters on which Mousson relied in 

 keeping it apart, namely the paucity (in addition to the obso- 



