MADEIRAN GROUP. 75 



Vitrina ruivensis (Couthouy), Gould, Proc. Bost. Soc. N.H. 



ii. 180 (1848) 



Pfeif.,Mon. Hel. ii. 507 (1848) 



Behnii, Lowe, Ann. Nat. Hist. ix. 112 (1852) 

 Teneriffse, Id. [nee Q. et 0. ; 1827], Proc. Zool. Soc. 



Lond. 163 (1854) 



ruivensis, Alb., Mai. Mad. 15. t. 2. f. 4-6 (1854) 

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

 ruivensis, Pfeiff., Mon. Hel. vii. 20 (1876; 

 Habitat Mad^ram ; in humidis editioribus, prsecipue sylva- 

 ticis, baud infrequens. In stratu conchylifero ad Canical semi- 

 fossilis parce reperitur. 



The Haliotis-sh&ped outline (the nucleus being lateral, 

 rather than subcentral), enormous aperture, and comparatively 

 depressed form of this large Vitrina, added to its fewer volu- 

 tions (there being only two of them, or at the utmost 2J), its 

 flattened apex and its consequently indistinct suture, will suffice 

 to separate it from the other species with which we are here 

 concerned. It is not quite so highly polished, usually, as the 

 V. nitida (i.e. the V. Lamarckii, Lowe, nee Fer) ; and there 

 are more appreciable indications beneath a high magnifying 

 power of a few minute, broken-up spiral lines, or (as it were.) 

 scratches. The obsolete transverse plicse, also, or folds, are, for 

 the most part, more curved and radiating. 



Although less common than the V. nitida, the present 

 Vitrina is tolerably abundant at a high elevation in Madeira 

 proper, where it occurs in the damp sylvan regions, principally 

 under stones and logs of decaying wood ; and it is found spar- 

 ingly, in a subfossil state, at Canigal. 



As regards its synonymy, this Vitrina is a little complicated. 

 Mr. Lowe originally cited it as a mere phasis of the ' V La- 

 marckii ' as understood by him (i.e. of the nitida, Gould), but 

 he afterwards published it (in 1852) as the V. Behnii in honour 

 of the Professor at Kiel, who had pointed out to him what he 

 conceived to be its true differential characters. But in the 

 meanwhile it had been (in 1848) described by Gould under 

 Couthouy's manuscript name ' ruivensis, 1 which seems to me 

 (as it did, apparently, to Dr. Albers) to be the oldest title for 

 the species on which we can absolutely depend. True it is 

 that Mr. Lowe, in his last enumeration of the Madeiran Mol- 

 lusca, identified it with the Canarian V. Teneriffce of Quoy and 

 Gaimard (which bears the date 1827): but then the V. Tene- 

 riffce proves to be identical with the genuine, and previously 

 described, V. Lamarckii (which is expressly registered by 

 Ferussac as having come from Teneriffe), as is manifest from 

 the diagnosis of it which is quoted by Pfeiffer, and as indeed 



