CAPE-VERDE GROUP. 499 



de S. Joao Batista, in Brava, adhering to the shrubs of Eu- 

 phorbia Tuckeyana, Webb, as well as under stones, at about 

 3,500 feet above the sea. 



Helix Bollei. 



Helix Bollei, Alb., Mai Bldtt. i. 215 (1854) 

 Pfei/; Mon - Hd. iv. 19 (1859) 

 Dohrn, Mai. Bldtt. xvi. 4 (1869) 

 Morel., Journ. de Conch, xiii. 235 (1873) 

 Habitat S. Vicente (sec. Dohrn et Morelet), et S. Nicol?o , 

 in intermediis editioribusque, sub lapidibus. 



This species and the following one, which I cannot but think . 

 will prove eventually to be but insular modifications of each 

 other, may be regarded as the representatives in the Cape- Verde 

 archipelago of the very variable Madeiran H. erubescens; 

 indeed (judging from the analogy of the latter, in its numerous 

 and very different phases) I am not at all satisfied that the 

 whole of them, including even the H. subroseotincta, are 

 anything more than local aspects of a single plastic type which 

 has permeated the length and breadth of this entire Atlantic 

 province. Still, since they have been published as specifically 

 distinct, and they can be recognised (not always, however, 

 without some difficulty) in a general way, I will not attempt to 

 do otherwise than cite them accordingly ; though I would wish 

 it to be understood that I look upon them, as regards their 

 differential characters, with a certain amount of distrust. 



With these observations, I may add that the H. Bollei seems 

 to be rather smaller and more pellucid than the leptostyla, and 

 usually of a pale yellowish-corneous hue, sometimes with a 

 faint rosy tinge, but apparently never fasciated or even blotched ; 

 its spire is just appreciably more obtuse or less elevated, with 

 the suture not quite so deeply marked ; its basal volution 

 (although obsoletely so) is more appreciably keeled ; the lower 

 lip of its aperture is not quite so rounded ; and its surface is 

 just perceptibly brighter, being altogether free, so far as I can 

 detect (even beneath a high magnifying power), from the ex- 

 tremely diminutive granules which are more or less traceable in 

 its ally. 



From the Madeiran H. erubescens the unwrinkled, unmal- 

 leated surface of the whole of these three immediately cognate 

 forms will, apart from other and less evident characters, at once 

 separate them. 



The H. Bollei was found both by Dr. H. Dohrn and Mr. 

 Lowe in S. Nicolao, where it would appear to be tolerably 

 common ; and, although I have not myself seen examples from 



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