300 TEST ACE A ATLANTIC A. 



Although a certain number of mere titles have been altered, 

 in this catalogue, consequent on the shells which they represent 

 having hitherto been wrongly referred to them, and which might 

 leave the erroneous impression, at first sight, that the species 

 themselves (rather than their names) had been rejected, there 

 are nevertheless twelve species, usually registered as Canarian, 

 which I would expunge altogether from the list, as having been 

 accepted upon evidence which is totally insufficient ; and since 

 the majority of them were equally doubted by Mousson, it is 

 much to be regretted that he should have admitted any of them 

 into his ' Eevision,' which certainly ought not to have been 

 augmented by forms which are so manifestly extraneous. The 

 twelve to which I allude are as follows : (1) Vitrina fasciolata, 

 Fer. ; introduced by the older naturalists, probably through a 

 mere confusion in the habitat as originally reported, its Canarian 

 claims having been disputed by even Webb and Berthelot. 

 (2) Hyalina semicostula. Beck ; a species found in Portugal, 

 and said by Reeve (Conch. Icon. 879), but without proper evi- 

 dence, to occur in Grand Canary. (3) Helix advena, W. et B. ; 

 a Helix which is now thoroughly demonstrated to be peculiar 

 to the Cape Verde archipelago, having no connection what- 

 ever with the Canaries, and one which (like so many other 

 species which were admitted by Webb, absolutely without proof 

 as to their precise countries, into his Canarian fauna) would 

 seem to have been obtained originally from bags of dried orchil, 

 or Dyers' lichen, which had been shipped to Europe for sale. 

 (4) Helix marcida, Shuttl. ; founded on a unique specimen in 

 the Marseilles Museum, imperfect and (according to Mousson) 

 ' dont 1'origine precise est inconnue; ' and in all probability there- 

 fore from the collection of M. Terver, by whom it must have been 

 found in the consignments of orchil to which I shall often be 

 compelled to allude as having been the occasion of so much un- 

 necessary error. (5) Helix melolontha, Shuttl. ; likewise 

 established on a single example in the Museum at Marseilles, 

 and from the cabinet of M. Terver, whose orchil-gathered ma- 

 terial has created an amount of confusion in the faunas of these 

 various Atlantic archipelagos which is simply deplorable. 

 (6) Helix tceniata, W. et B. ; an essentially Madeiran form, 

 absolutely peculiar to Madeira proper, and not permeating even 

 the other islands of that archipelago, and doubtless obtained by 

 Webb (through M. Terver, of Lyons) from casks of orchil, or 

 ' Dyers' Moss.' (7) Helix tiarella, W. et B. ; likewise empha- 

 tically Madeiran, and thoroughly distinctive of that archipelago, 

 having unquestionably come into the hands of Webb (who had 

 no scruple in citing it as Canarian) along with the H. tccniata. 

 (8) Bulimus Terverianus, W. et B. ; a species belonging to 



