MADEIRAN GROUP; 



'301 



Helix Webbiana, Pfeiff., Mon. Hel. i. 219 (1848) 



Lowe, Proc. Zool. Soc. Loud. 197 (1854) 



Alb., Mai. Mad. 53. t. 14. f. 13-15 



(1854) 



Paiva, Mon. Moll. Mad. 98 (1867) 



Vitrina Bocagei, Paiva [testa junior] 1. c. 10. t. 2. f. 6 

 (1876) 



Habitat Portum Sanctum, et ins. parvam adjacent em ' Ilheo 

 de Cima ' ; sub lapidibus in graminosis montium degens. In 

 statu semifossili parcissime reperitur. 



This most remarkable of the Helices of the Madeiran archi- 

 pelago appears to be confined to Porto Santo, and the little 

 adjacent island of the ' Ilheo de Cima ' (where it was taken 

 sparingly by Senhor J. M. Moniz) ; and, although not very 

 generally abundant, it is locally far from uncommon, beneath 

 stones, and usually at a rather high altitude. It is true tnat 

 the Baron Paiva cites it as occurring likewise on the Southern 

 Deserta ; but I can only say that no traces of it were observed 

 there either by Mr. Leacock, Mr. Lowe, or myself, and that 

 until further evidence therefore has been adduced I shall 

 refuse to regard it as in any way connected with that remote 

 and little-known rock, and more particularly so, since the 

 Baron's material was seldom, if ever, obtained by himself, but 

 was merely brought to him (at intervals) by paid collectors 

 sent out from Funchal. But on many of the higher mountain- 

 slopes of Porto Santo it has been met with by Mr. Lowe, Mr. 

 Leacock, myself, and others, in tolerable numbers, especially 

 on the ascent of the Pico Branco, the Pico do Concelho, aL.d 

 the Pico de Baixo. In a subfossil condition it is scarce, but 

 was taken by Mr. Lowe and myself at the Zimbral d'Areia, and 

 in several of the other calcareous deposits. 



In the paucity of its whorls, its brownish-green hue, its 

 thin, shining, subpellucid substance, its total freedom from an 

 umbilicus, its enormous aperture, and in its upper and lower 

 lips being quite unconnected by a corneous lamina, the H. 

 Webbiana has a slight prima facie element in common with 

 the genus Vitrina ; ! and it is further conspicuous by its 

 acutely developed keel, and by the fact of its being more or 

 less studded with coarse and remote granules, which however 

 become gradually evanescent towards the inner portion of the 

 (very obliquely striated) volutions. Its peristome is a good deal 



1 It is remarkable that the Vitri<na Bocagei of Paiva {Mon. Moll. Mad. 10. 

 t. 2. f. 6), recorded (evidently through an error) to have been taken in Madeira 

 proper, was established, as I am assured by the Kev. R. B. Watson, on an 

 immature example of the Helix Webbiana ! "(cf. t also, Journ. de Conch. 219 ; 

 1876.) 



