368 TEST ACE A ATLANTIC A. 



might possibly be looked upon as permanent insular phases of 

 the Teneriffan type, no such conclusion could be arrived at in 

 the case of the one now under consideration, seeing that it in- 

 habits the same island (and has done so since the subfossil epoch) 

 as the malleata proper. Apart also from its diagnostic cha- 

 racters, which are both numerous and striking, the habitats of 

 the species in question seem quite dissimilar ; for while the 

 H. malleata is essentially sylvan in its mode of life, occurring 

 normally from about 2,000 to 3,000 feet above the sea, the H. 

 nivarice, on the contrary, is found in comparatively low and 

 arid spots towards the northern coast, the examples before me 

 having been taken by Mr. Lowe near the Puerto of Orotava, 

 where it exists both in a recent and a semifossilized condition. 



The H. nivarice is larger and relatively perhaps is little more 

 depressed than the malleata, and (except in its central area 

 beneath) it will be seen, when viewed under a high magnifying 

 power, to be everywhere crowded with infmitesimally minute 

 sand-like granules (far smaller than those which are so conspi- 

 cuous in the Grand-Canarian H. Glasiana), a peculiarity of 

 sculpture which causes the surface (which is equally malleated, 

 though less richly coffeaceo-olivaceous) to be less glossy than in 

 that species. Its ultimate volution (which is free from all ap- 

 pearance of a keel even behind) is less deflected in front, and 

 more gradually so ; its aperture (which is small) is much more 

 triangular in outline ; and its peristome, which is more thick- 

 ened and convex within, but more acute, more produced, and 

 more reflexed externally, has the margins much wider apart at 

 their points of insertion, the basal one, moreover, being more 

 straightened, and the upper one having the two teeth quite ob- 

 solete, or sometimes faintly represented by a slight thickening, 

 or callosity, in the usual places. 



Helix Grlasiana. 



Helix malleata, ., Pfei/., Mon. Hel. i. 312 (1848) 

 G-lasiana, Shuttl., Bern. Mitth. 143 (1852) 

 pellis-lacerti, Reeve [teste Pfeiff.], Conch. Icon. t. 132. 



n.841 

 Mouse., Faun. Mai. des Can. 92 



(1872) 

 Pfeiff., Mon. Hel. vii. 359 



Habitat Canariam Grandem ; in intermediis, prsecipue per 

 regionem El Monte, in Caldeira magna montis Bandama, nec- 

 non in calcareis inter oppida Lagaete et Gaidar, occurrens. In 

 statu semifossili ad calcareos inter Las Palmas et Puerto da 

 Luz copiose inveni. 



