MADEIRAN GROUP. 97 



vulgatissima. Necnon in solo arenoso semifossilis occurrit. 

 Var. 8. craticuata ad insulam ' Ilheo de Ferro ' solum recens 

 pertinet ; sed in statu semifossili in Portu Sancto ipsissimo 

 late reperitur. 



This is one of the most abundant and universal of the 

 Helices of Porto Santo, to which island, and the immediately 

 adjacent rocks, it would seem to be peculiar ; and it is tolerably 

 common in a subfossil state, particularly under the phasis 

 which I have cited as the ' 8. craticulata, Lowe, which in a 

 recent condition occurs now only on the Ilheo de Ferro. 



The H. phlebophora may be known by its more or less 

 globose, strictly Helix-shaped, or subtrochiform, contour, and 

 by its variegated (or fasciated) surface, which is more or less 

 coarsely molleate and beset with oblique and very irregular sub- 

 confluent costate lines, a peculiarity of sculpture which im- 

 parts a wrinkled appearance to the whole. 



The present species, however, passes through many degrees 

 of colour, outline, and sculpture, the four principal ones being 

 [1] the normal state (corresponding with the 'a. chlorataj 

 Lowe), in which the shell is comparatively globose, and the 

 corrugations of the surface are more developed than the costse ; 

 [2] a more depressed form (answering to Lowe's ' /3. planata '), 

 in which the spire is a little less raised, the surface, on the 

 average, a trifle paler and more variegated (the bands being 

 narrower, and more broken-up or interrupted), and in which 

 the oblique irregular costae are more sharply developed ; [3] a 

 yellowish-white, almost colourless or albino variety, free from 

 fasciae and markings but otherwise agreeing with the c a. 

 chlorata, Lowe, and which represents the H. nivosa of 

 Sowerby ; and [4] a smaller, darker, and a more beautifully 

 dappled phasis, with the corrugations very coarse and large but 

 with the ridges almost obsolete, and with the spire relatively a 

 little more elevated, peculiar apparently (at any rate in a recent 

 condition) to the small islet known as the Ilheo de Ferro 

 (where it was first detected by myself), and which was de- 

 scribed by Mr. Lowe in 1852 (under the name of H. craticulata) 

 as distinct, but which in 1854 he suppressed as a species, citing 

 it as the ' var. 8. scrobiculata ' of the H. phlebophora. 1 



1 By a glance at the synonyms given above, it will be seen that in reality 

 Sowerby's name ' nivosa ' is the prior one for this Helix, by many years, it 

 having been published in 1824, whereas Mr. Lowe's * phUbojihora ' did not 

 make its appearance until 1831. If therefore it be insisted that priority out- 

 weighs every other consideration whatsoever (even, for instance, the employ- 

 ment of a title which conveys an absolutely false idea of the species to which 

 it has reference), the change in the nomenclature must of course be made. 

 Under ordinary circumstances I should myself have made it ; but since the 

 name pklebophora has almost universally been allowed for this Helix, on 



