132 TEST ACE A ATLANTICA. 



his habitat and figures) for the H. s'pivorhw, Lowe, which 

 appears really a good species. He cites them, very properly, as 

 a ' var. /3. minor ' of the H. 'maderensis, — adding ' Varietas ^. 

 [which, however, he wrongly identifies with the H. spirorbis'] 

 in locis apricis siccissimis reperitur," — clearly not being aware 

 that the only region in Madeira proper in which the H. spir- 

 orbis has hitherto been observed is towards Feijaa d'Ovelha and 

 Paul do Mar (a distant and little-known locality which Dr. 

 Albers certainly never visited). 



The H. rnaderensis seejns to be confined (like the very 

 much rarer and more local H. compar and twniata) to jNIadeira 

 proper, where it is one of the most abrmdant of the Helices ; 

 nevertheless, although so common, it is extremely circumscribed 

 in its distribution, — it being well-nigh confined to the hot sea- 

 cliffs, and submaritime hills, which form the lower, and outer, 

 zone of the island. It occurs from the level of the sea to an 

 altitude of about 2,000 feet, often swarming in dry and semi- 

 cultivated grounds. 



Helix spirorbis. 



Helix spirorbis, Loive, Ann. Nat. Hist, ix (1852) 

 „ maderensis, var. /8., Pfeif. [sec. Albers^, Mon. Hel. 



'iii. 164 (1853) 

 „ spirorbis, Lowe, Proc. Zool. Sac. Lond. 195 (1854) 

 „ „ Paiva, Mon. Moll. Mad. 52 (1867) 



Habitat Maderam, et (sec. Paiva) Desertam Australem; in 

 collibus aridis apricis submaritimis, pra?cipue juxta Feijaa 

 d'Ovelha sub lapidibus congregans. 



This is the smallest of the H. maderensis group, and a form 

 which, m its more granulate, less banded surface, and somewhat 

 thinner substance, makes a manifest approach to the leptosticta 

 type ; though its relatively much larger umbilicus, its coarser 

 granulations, and the fact of its fasciae (however obscure) being 

 at any rate both more conspicuous than in that well-nigh uni- 

 colorous species (the under one, when present, being moreover 

 dinerently placed) will immediately remove it from the latter. 



The present Helix is more intimately related to the H. 

 maderensis than it is to anything else, nevertheless I think that 

 Mr. Lowe was perfectly justified in separating it therefrom, — 

 its smaller size and more obtuse spire, added to its slightly less 

 solid and more transparent texture, its appreciably wider um- 

 bilicus, its more convex volutions and more deeply impressed 

 suture (the former of which are only 6 in number, instead of 7), 

 and its diff"eient colour and sculpture, giving it a character 

 essentially its own. As regards colour indeed, the ordinary 

 fasciic of the H. madereyisis type are in the //. spirorbis occa- 



