MADEIRAN GROUP. 221 



ciably banded. Its aperture too is not exactly similar, the 

 sphincter, which joins the first ventral plait with the angle of 

 the lip, being less thickened and differently shaped ; whilst the 

 palatial plaits, which are so strongly developed (although deeply 

 immersed) in the P. sphinctostoma, seem in the laurinea to be 

 reduced (from three) to one, the upper and lower ones being 

 apparently obsolete. 



From the P. Loweana the laurinea may be known by being, 

 inter alia, rather paler and more shining (or less appreciably 

 striate), and also more decidedly banded : its outline too is 

 more oval (or less ovate), not being so much widened posteriorly ; 

 its aperture is more produced downwards (instead of outwards) ; 

 and the sphincter which connects the angle of the lip with the 

 first ventral plait is usually very much less thickened or de- 

 veloped. 



The P. laurinea occurs chiefly about the trunks of old 

 laurels in the sylvan districts of intermediate altitudes. It has 

 been taken by Mr. Lowe (and also more sparingly, by myself 

 and others) in various places, such as the Eibeiro Frio, S. An- 

 tonio, da Serra, and the Boa Ventura. In a subfossil state, it is 

 not very uncommon at Canipal. 



Pupa Wollastoni. 



Pupa Wollastoni, Paiva, Crosse, Journ. de Conch. (Oct. 



1866) 

 canicalensis, Id., Mon. Moll. Mad. 131 (1867) 



Habitat Maderam, in stratu conchylifero ad Canipal semi- 

 fossilis lecta ; recens hodie non observata. 



As already implied under the P. deformis, the present Pupa 

 was enunciated by the Baron Paiva in October 1866 as the P. 

 Wollastoni a name which he suppressed (in his Monograph) 

 during the following year, in favour of a newly -suggested one 

 (P. canicalensis), the title 6 Wollastoni'' having been inadvert- 

 ently selected by Mr. Lowe for another member of the same genus 

 after the publication of his (the Baron Paiva's) diagnosis in 

 Crosse's Journ. de Conchyliologie. I need here therefore only 

 repeat, that I have no option but to restore for the subfossil 

 species from Canipal the name originally proposed for it by the 

 Baron, the latter in reality not having the poiver to violate 

 the acknowledged law of priority, which requires absolutely that 

 a title once given, unless afterwards found to be either pre-occu- 

 pied or utterly inappropriate, cannot under any circumstances be 

 changed. I have therefore, in this instance, adhered to the name 

 which was first given by the Baron Paiva, and have proposed a 

 new one for the P. Wollastoni of Lowe. 



