MADEIRAN GROUP. 129 



elevated ridges or with smaller and more densely packed costate 

 lines ; and they have usually a single narrow fascia (rarely 

 absent) both above and below the keel. 



The H. compar is remarkable for the coarse and powerfully 

 raised, equidistant, whitish, oblique, transverse costse with 

 which it is furnished both on its upper and its under side, and 

 for its total freedom from all other sculpture, there being no 

 indication of intervening granules even towards the aperture. 

 It is intimately related to the H. maderensis, of which it has 

 occasionally been looked upon (perhaps without sufficient reason) 

 as an extreme development ; nevertheless, apart from the pecu- 

 liarities of its sculpture (which are so marked and conspicuous), 

 its basal volution is very decidedly less angulated or keeled, its 

 aperture is less suddenly deflected, its umbilicus is just appre- 

 ciably larger, and (although possessing the same single darker 

 band both above and below) its general colour is, on the average, 

 somewhat deeper and richer. 



It is chiefly about the Cabo Grirao, the great south-western 

 promontory of Madeira proper, that the H. compar is found 

 (indeed I am not aware that it has been observed hitherto in 

 any other district), where it was first met with by Mr. Lowe, 

 during December of 1828, on the Pico do Rancho (a lower 

 offshoot, or semi-detached compartment, of the Cape Grirao) ; 

 and the Baron Paiva records its occurrence nearer to, and 

 around, the village of Camara de Lobos. 



Helix taeniata. 



Helix tseniata, W. et #., Ann. des Sc. Nat. 28. Syn. App. 



224 (1833) 

 d'0r6., in W. et B. Hist. 63. t. 3. f. 18-20 



(1839) 



Pfeiff., Mon. Hel. i. 189 (1848) 

 maderensis, major, Lowe, Proc. Zool. Soc. Lond. 195 



(1854) 

 tseniata, Mouss., Faun. Mai. des Can. 57 (1872) 



Habitat Maderam ; in collibus maritimis, prsecipue occi- 

 dentalibus et prsecipue versus Paul do Mar, sub lapidibus con- 

 gregans. [Etiam in ins. Canariensibus a cl. Webb occurrere 

 dicitur ; sed procul dubio ex exemplaribus Maderensibus, in 

 sarcinis Roccellce tinctorice lectis, descripta.] 



It is rather surprising that so accurate an observer as Mr. 

 Lowe should have failed to perceive anything about the present 

 Helix except its larger size, to distinguish it from the common 

 H. maderensis, for its characters seem to me to render it 

 quite as worthy of specific separation as those of the H. compar 



