26 TEST ACE A ATLANTIC A. 



hue) throughout the Madeiran archipelago, occurs in the orange 

 grounds of S. Miguel, both around Ponta Delgada, &c., and 

 even (according to Morelet) in the valley of the Furnas ; and 

 considering this singular limitation of its habitat, we may feel 

 tolerably sure that the species is not an aboriginal native of the 

 Azores, but that in all probability it has become naturalized 

 accidentally from Madeira. The fact too that it appears to be 

 confined to a single island of the Group, and that one the most 

 cultivated of them all, is quite in accordance with this supposi- 

 tion. Both Morelet and Drouet lay great stress on the curious 

 fact that it would seem to be attached exclusively to the gardens 

 and plantations where the orange-trees are grown, concealing 

 itself more especially within the fissures and cavities of the 

 trunks, often in large clusters. 



Drouet says that at Madeira the H. erubescens is found 

 essentially in woods, but this is absolutely untrue ; for although 

 it does occasionally make its appearance in subsylvan spots, as 

 in the chestnut groves of intermediate altitudes, its normal 

 range is most unmistakeably beneath stones on the open moun- 

 tain slopes (as on the grassy declivities of the Pico da Silva, 

 &c.), and within the lichen-covered inequalities of the weather- 

 beaten rocks. Indeed on the three Desertas, where it absolutely 

 swarms, there is not so much as a single tree for it to inhabit ; 

 and even in Porto Santo, the higher districts (to which it is 

 confined) are, and clearly always have been, totally devoid of 

 wood. 1 



1 Although it is well-nigh superfluous to do so, I may perhaps just notice 

 in this place the H. advena, W. et B., which is cited bj Morelet, as one of 

 his 69 species, on the strength of its having been recorded by Pfeiffer as 

 occurring not merely at the Cape Verdes [to which it is, nevertheless, abso- 

 lutely peculiar], but also in the Canaries and Azores. And he even goes on 

 to affirm that Madeira likewise must be added to its range, inasmuch as 

 Albers includes it in his [extremely inaccurate] ' Malacographia Maderensis ' ; 

 so that, according to him, elle est repandue dans les quatre archipels.' 

 Here then is an accumulation of blunders, both as to habitat and identifi- 

 cation, which it is perfectly sad to contemplate. In the first place, the H. 

 advena is confined exclusively to the Cape Verdes ; the examples which Dr. 

 Albers referred so unhesitatingly to that species, and which he said were 

 found by M. Hartung in Porto Santo, having nothing whatever to do with it. 

 And then, as regards its Canarian claims, I thought it was now generally 

 understood that it was through the excessive carelessness of Mr. Webb that 

 it was ever quoted amongst the Land-Mollusca of that archipelago at all ; 

 for, unless I am greatly mistaken, it was communicated originally to the 

 joint authors of the ' Histoire Naturelle,' along with the equally Cape- Verdian 

 Stenogyra subdiapkana, by M. Terver, of Lyons, whose orchil-infesting 

 Helices (the precise countries of which were guessed at with a recklessness 

 almost unparalleled) have been the means of creating an amount of geo- 

 graphical confusion which perhaps will never be altogether obliterated. 

 This unpardonable mode of treatment was inflicted on other species also, 

 besides those to which I have just called attention, notably on the H. 

 taniata and tiarella of Madeira, which were pronounced to be ' Canarian,' 



