76 TEST ACE A ATLANTIC A. 



has recently been acknowledged by Mousson. Moreover it is 

 evident that Mr. Lowe was mistaken in the opinion which he 

 had adopted both of the F. Teneriffce and of the V. Lamarckii 

 (which, as just stated, are one and the same species) ; for he 

 assumed the former to be identical with the Madeiran V. rui- 

 vensis (which is also his V. Behnii\ and the latter with the 

 other (and more common) Madeiran Vitrina which was de- 

 scribed by Gould (in 1846) under the name of nitida. So that 

 I come to the conclusion, that the title ruivensis is the oldest 

 reliable one for our present species. 



Vitrina marcida. 



Vitrina marcida, Gould, Proc. Bost. Soc. N. H. ii. 181 



(1848) 



Pfeiff., Mon. Eel. ii. 507 (1848) 



media, Lowe, Proc. Zool. Soc. Loud. 164 (1854) 

 marcida, Paiva, Mon. Moll. Mad. 9 (1867) 

 Pfeiff., Mon. Hel. vii. 21 (1876) 



Habitat Portum Sanctum vulgaris, sed in Madeira rarior ; 

 locos humidos editiores praecipue colens. 



I am exceedingly doubtful whether this is anything more 

 than a smaller state of the V. nitida (i.e. of the V. Lamarckii, 

 Lowe, nee Fer.), with which in its outline, and in the relative 

 proportions of its aperture, it agrees almost exactly. But, 

 apart from its (on the average) distinctly reduced size, it is 

 further characterized by being almost always of an appreciably 

 paler tint, in its spire being more depressed (though not quite 

 so flattened as in the V. ruivensis), indeed in its general con- 

 tour being a trifle less inflated or convex, and in its lower lip 

 being more broadly and conspicuously membraneous. It has 

 usually, too, half a volution less than the F. nitida ; and there 

 are for the most part more evident indications of a few abbre- 

 viated radiating plicae just below the suture (and towards the 

 aperture) of the basal whorl. 



The F. marcida is extremely common on the mountains of 

 Porto Santo, where it occurs about damp rocks, and under 

 stones in moist grassy places, at a rather high elevation. I am 

 not quite sure that I have myself met with it in Madeira pro- 

 per ; nevertheless it is recorded by Mr. Lowe from the Eibeiro 

 Frio, and it appears to have been found in other sylvan spots 

 of an intermediate altitude. 



Vitrina nitida. 



Helicolimax Lamarckii, Lowe [nee Fer. ; 1822], (pars), 



Zool. Journ. iv. 338-344 (182U) 



