CAPE-VERDE GROUP. 501 



that it has been found by MM. Bouvier and de Cessac in S. Ni- 

 colao and Maio. Nevertheless it is perhaps open for enquiry 

 whether the examples from S. Nicolao are not in reality refer- 

 able to Albers' H. serta. It was manifestly through an error 

 that Webb described it originally, in his ' Synopsis,' as coming 

 from the Canaries ; but his extreme carelessness as regards his 

 habitats was well known to those who (like Mr. Lowe) were in 

 communication with him at the time, and it would appear that 

 another Cape-Verde species (namely the Stenogyra subdia- 

 phana) shared the same fate as the present one, and was wrongly 

 introduced into the fauna of that Group. 1 



Mr. Lowe, in his last catalogue of the Madeiran Land-Mol- 

 lusca (Proc. Zool. Soc. Lond. 165 ; 1854), identified Webb's H. 

 advena with the particular state, or variety, of the erubescens 

 (well enunciated by the Baron Paiva under the name of ' 7. ad- 

 venoides'') which obtains on the Sao Lourenco promontory of 

 Madeira proper, and which is still more characteristic of the 

 Northern Deserta (or Ilheo Chao) ; but in this he was evidently 

 mistaken, Mr. Edgar Smith having examined for me with great 

 care one of the original types (now in the British Museum) on 

 which the H. advena was founded, and which he assures me is, 

 without any doubt whatsoever, identical with the Cape-Verde 

 species, — thus corroborating the conclusions which had pre- 

 viously been arrived at by Dohrn and others. 2 Dr. Albers, in 



1 Indeed Madeiran species likewise would appear to have been pressed 

 recklessly into his service, — the H. tiarella and tcenicuta, both essentially 

 characteristic of Madeira proper, having been made to figure in the Canarian 

 list; as was also the Bulimus Terverianns, from Morocco. 



2 Since the above was written I have myself inspected these British 

 Museum types of the H. advena ; and if the species is to be settled by the 

 majority of the individuals which are placed to represent it, there is fortu- 

 nately no question that the H. advena is truly (as has latterly been supposed) 

 the Cape Verde shell which we are now considering ; for out of the three 

 examples (all more or less immature) which are there preserved, as having 

 formed a portion of Webb's so-called * Canarian ' material, two are un- 

 doubtedly our present Helix. The third (or central) one, however, does not 

 appear to me to be specifically identical with the others, — its malleated, and 

 less coarsely and much less regularly striated, surface (which is likewise very 

 minutely granulose) affiliating it, I think, unmistakeably, with the Madeiran 

 H. erubescens (perhaps under its Desertan aspect). Tnus if Mr. Lowe ex- 

 amined this particular specimen only, his conclusions concerning the H. ad- 

 vena were probably correct ; but the other two individuals constitute a 

 majority which give a different verdict. At any rate it is quite in harmony 

 with the characteristic carelessness of Mr. Webb on the subject of habitats, 

 that of these three immature Helices (gathered from consignments of dried 

 orchil) which he so unhesitatingly published as ' Canarian,' two should prove 

 to be from the Cape Verdes and the other from Madeira ! But this, un- 

 fortunately, is not the whole of it ; for we were required also to believe, by 

 these very confident probers of ' dyers' moss,' until at least it was shewn to 

 be absolutely absurd, that the H. advena was a native likewise of the 

 Azores! Perhaps, however, the mi.cing-up of the Cape Verde shell with the 

 real erubescens may possibly account for a certain percentage of all this 

 confusion. 



