MADEIRAN GROUP. 203 



receiving it, and more especially so since the recently discov- 

 ered H. galeata,, which is but just separable from the calva, 

 has a very marked analogy, in its general proportions and obtuse 

 helmet-shaped (or somewhat cupola-like) outline, with the Cana- 

 rian H. lemniscata ; whilst the H. calva itself has some remote 

 points of contact, both in habits and in structure, with the 

 H. Michaudi, Desh., and perhaps with even (though this is 

 more doubtful) the H. monilifera, W. et B. Still, the well- 

 nigh unornamented surface and thicker substance, added to the 

 minute spiral lines, of both the calva and galeata, isolate them, 

 to a certain extent, from -these immediate forms. 



Apart from its spiral lines above mentioned (which, however, 

 although of considerable significance, are nevertheless so minute 

 as to be appreciable only beneath a high magnifying power), and 

 its small and nearly concealed umbilicus, the H. calva may be 

 further known by its almost uniform pale-brown, or yellowish- 

 corneous, hue (the two fasciae, although occasionally conspicuous 

 on the basal whorl, being for the most part obsolete) ; and by its 

 upper region being nearly opake and sculptured with coarse and 

 irregular, but oblique and curved, costse, whilst beneath it is more 

 shining and less roughened. 



The H. calva is confined exclusively to Madeira proper, where 

 it is locally abundant, for the most part beneath stones on the 

 grassy mountain slopes of a high elevation, ascending from about 

 2,500 feet above the sea to the summits of the peaks. It is also 

 extremely common in a subfossil state at Canical (in company 

 with various Helices and Pupce), having doubtless been washed 

 down to that comparatively low region, at some remote period, 

 from the neighbouring heights, under conditions, and influences, 

 of the surrounding country, which were totally different from 

 those which now obtain. 



Helix galeata. 



Helix calva, 7. galeata, Lowe, Ann. Nat. Hist. (1862) 

 galeata, Pfeiff., Mai. Bldtt., March. (1864) 

 Paiva, Mon. Moll. Mad. 37. t. 1. f. 2 (1867) 



Habitat Maderam ; a Baron e Castello de Paiva in Bibeira 

 do Fayal, prsecipue ad .radices Pteridis aquilince adhserens, 

 A.D. 1861, sat copiose reperta. 



The H. galeata was detected by the Baron Paiva in Madeira 

 proper, in 1861 ; and Mr. Lowe, in his notice of it in the ' Ann. 

 of Nat. Hist.' for the following year, arrived at the conclusion 

 that it is only an extremely developed and obtusely-conical, or 

 beehive-shaped, modification of the H. calva, -imagining that 

 it might be connected, or nearly so, with the type, by certain 



