500 T^STACEA ATLANTIC A. 



that island, it is recorded both by Dohrn and Morelet to have 

 been taken on Monte Verde in S. Vicente. 



Helix leptostyla. 



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

 „ „ Morel., Joiirn. de Conch, xiii. 242 (1873j 



Pfeiff., Mon. Hel. vii. 59 (1876) 



Habitat S. Antao ; a cl. H. Dohrn benigne communicata. 



As already implied, this Helix (which has been communi- 

 cated by Dohrn, as found in S. Antao) may be regarded, in 

 conjunction with the preceding one, as the Cape-Verde repre- 

 sentative of the Madeiran H. eruhesc&ns, — to which indeed, in 

 its rather larger size and more highly coloured (often fasciated) 

 surface it makes a still nearer approach. Nevertheless, its 

 totally unwrinkled, unmalleated, and more granulose sculpture 

 will, of itself, remove it from all the numerous phases of that 

 protean species. 



The H. leptostyla (which in its young state is rather sharply 

 carinated) appears to be a trifle larger (on the average) than 

 the H. Bollei, as well as a little thicker in substance or less 

 pellucid : and it is also more variegated (having a greater ten- 

 dency to be both fasciated and dappled), somewhat less shining, 

 and (when viewed beneath a high magnifying power) very 

 diminutively granuled. Its ultimate volution is just appre- 

 ciably more ventricose, or less keeled, its lower lip is per- 

 ceptibly more rounded, and its spire is a little more elevated or 

 less obtuse. 



Helix advena. 



Helix advena, W. et B., Ann. des Sc. Nat. 28. syn. 324 

 (1833) 

 „ „ dVrb., in W. et B. Hist. 58. t. 1. f. 18-20 



(1839) 

 „ „ Pfeif., Mon. Hel. i. 270 (1848) 



„ „ Dohrn, Mai. Bldtt. xvi. 5 (1869) 



„ „ Morel., Journ. de Conch, xiii. 232 (1873) 



Habitat S. Antao, et S. Vicente, necnon sec. Morelet S. Ni- 

 colao et Maio ; sub lapidibus in intermediis, hinc inde vulgaris. 

 In S. Antao quoque semifossilis reperitur. 



This seems to be one of the most generally distributed of the 

 Helices which are peculiar to the Cape Verde archipelago ; for 

 although it is only in S. Vicente that I have myself met with it 

 (where I obtained it in great profusion, beneath stones, on the 

 ascent of Monte Verde), it was taken by Dohrn (both recent and 

 in a subfossilized condition) in S. Antao, and Morelet reports 



