414 TEST ACE A ATLANTIC A. 



Teneriffe were obtained chiefly around Sta. Cruz, Souzal, 

 Orotava, and Orarachico ; and the Gromeran ones from San 

 Sebastian and Hermigua. But there is hardly a district, pro- 

 vided it be sufficiently arid and at not too high an elevation, in 

 which it will not be found to occur. 



The H. monilifera is (as compared with its immediate 

 Canarian allies) a solid, and rather globose but at the same 

 time more or less depressed little shell (both above and below), 

 with its perforation very minute and almost concealed (in adult 

 examples) by the reflexed columellary portion of the peristome, 

 and with a raised whitish ring-like rib within the (acute) edge 

 of its aperture. Although its spire is not usually much elevated, 

 the volutions are convex, and densely sculptured with the 

 oblique striae of growth. And its surface is either white or 

 brownish- white, and elegantly fasciated with two more or less 

 distinct darker bands, one of which is on the underside, 

 becoming gradually lost sight of within the aperture, whilst 

 the other is above the dorsal line, usually much broken-up (or 

 interrupted by irregular transverse white blotches), and con- 

 tinued along the whorls (more or less broadly and conspicuously) 

 to nearly the apex. This arrangement of colouring gives the 

 entire shell, for the most part, an extremely mottled appearance. 



I have already stated under the H. lancerottensis (vide, 

 ante-) p. 378), that an old, bleached, and decorticated example 

 of this common Canarian shell was described by d'Orbigny as 

 actually the type of that species, of which he considered that 

 he had never seen more than the single individual from which 

 his diagnosis was drawn out ! And this is all the more un- 

 pardonable since the lancerottensis and monilifera are in 

 reality quite distinct in structure, and both of them had been 

 characteristically enunciated by Webb six years before, the 

 well-engraved plates, moreover, which had been completed by 

 Terver under Webb's superintendence long previous to d'Or- 

 bigny's engagement in his portion of the ' Histoire Naturelle,' 

 leaving the features of the two species quite unmistakeable. 



Helix lemniscata. 



Helix lemniscata, W. et ., Ann. des Sc. Nat. 28. 317 



(1833) 

 d'Orb., in W. et B. Hist. 6. t. 1. f. 23 



(1839) 



Pfeiff~> Mon. Hel. i. 156 (1848) 



Mouss., Faun. Mai. des Can. 46 (1872) 



Habitat Canariam Grandem; in intermediis prsecipue oc- 



