216 TESTACEA ATLANTICA. 



is often whitish and decorticated ; but its aperture (which is less 

 outwardly, or more downwardly, produced than is the case in its 

 immediate allies) contains the characters which will more quickly 

 discriminate the species, the five plaits, especially the outer 

 ventral one (which is sinuate, and united to the angle of the lip 

 by a thick corneous rim or sphincter), being very largely deve- 

 loped, even the upper one of the columella (although smaller 

 than the lower) being exceedingly conspicuous. The tooth of 

 the labrum (which is a good deal nipped-in at that particular 

 point) is rather thick and internally prominent, almost closing 

 up (the result, however, partly, of the flexuosity of the first 

 ventral plait) the ' sinus respirationis.' 



The P. irrigua, although locally abundant, appears on the 

 whole to be somewhat scarce, occurring more, however, so far 

 as has hitherto been observed, in the south of Madeira, than the 

 north. It inhabits the muddy and Marchantia-padded deposits 

 of the damp, trickling rocks, in the shady ravines of intermediate 

 altitudes, adhering likewise to the wiry roots of the coarse grasses 

 which hang loosely in the constant drip of such localities. It 

 was taken in great profusion by Mr. Lowe and myself, on various 

 occasions, on the perpendicular face of lofty rocks on the right 

 (or eastern) side of the Ribeira de Sta. Luzia, about two-thirds 

 of the entire distance up, and therefore about one-third below 

 the waterfall. Judging also from the Baron Paiva's material, 

 he seems to have obtained it sparingly from the north of the 

 island, a few examples being mixed up with his large batches 

 of the P. Loweana and the P. vincta. 



Pupa deformis. 



Pupa Wollastoni, Lowe [nee Paiva, 1866], Ann. Nat. 



Hist. 81 (1867) 



Paiva [nee Id., 1866], Mon. Moll. 



Mad. 128 (1867) 



Habitat Maderam borealem, semel lecta ; a Bar one Castello 

 de Paiva communicata. 



I am extremely sorry to be compelled to change the name 

 of this remarkable Pupa, which was enunciated by Mr. Lowe 

 in 1867 as the ' P. Wollastoni ; ' but that title having been pre- 

 occupied by the Baron Paiva in the previous year for a subfos- 

 sil species from Canipal, justice requires that the latter should 

 take the precedence. It is true that the Baron, in his late 

 Monograph, suppressed his previously-published name, in con- 

 sideration of Mr. Lowe having subsequently selected the same, 

 proposing, instead, for his ' P. Wollastoni^ the trivial one of 

 canicalensis. But I can only add that in reality he had not 



