MADEIRAN GROUP. 95 



is more particularly dominant, and where it may be said to 

 attain its maximum. In the central island it just makes its 

 appearance, on the abrupt eastern side (towards the south), in a 

 spot known as the Feijaa Grande ; where however the specimens, 

 which we may register as the ' var a. intermedia^ are (on the 

 average) a little smaller and darker than those from the Bugio. 



Helix undata. 



Helix undata, Lowe, Gambr. Phil. S. Trans, iv. 41. t. 5. f. 

 5 (1831) 

 „ „ Pfeiff., Mon. Hel. i. 191 (1848) 



„ „ Lowe, Proc. Zool. Soc. Lond. 168 (1854) 



„ „ Alb., Mai. Mad. 50. t. 13. f. 13-16 (1854) 



„ „ Paiva, Mon. Moll. Mad. 16 (1867) 



Habitat Maderam ; sub lapidibus necnon ad muros, prsecipue 

 in cultis inferioribus, congregans. In stratu conchylifero ad 

 Canical semifossilis occurrit. 



This is one of the most universal, and characteristic, of the 

 Land-Shells of Madeira proper, — to which island it would seem 

 to be peculiar, and where it often swarms, beneath stones and 

 about old walls, chiefly at rather low elevations and in cultivated 

 spots ; and it occurs likewise in a subfossil state, though in no 

 great profusion, at Canical. 



The H. undata is more nearly related to the H. Vulcania 

 and leonina, of the Desertas, than to any other species which 

 has hitherto been brought to light. Indeed with the ' var. a. 

 intermedia'' of the latter, from the Deserta Grande, it has a 

 good deal in common ; nevertheless it is considerably smaller 

 and less inflated (or globose), even still more undulate in its 

 sculpture, and also of a uniform and paler brown, — there 

 being no traces whatsoever of fascia, or bands, on any of the 

 volutions. 



(§ Katustoma, Lowe.) 



Helix psammophora, 



Helix psammophora, Lowe, Ann. Nat. Hist. ix. 113 (1852) 

 „ „ Id., Proc. Zool. Soc. Lond. 166 (1854) 



„ „ Alb., Mai. Mad. 83. t. 17. f. 15 



(1854) 

 „ „ Paiva, Mon. Moll. Mad. 16 (1867) 



Habitat Portum Sanctum, hodie recens non inventa ; in 

 arena calcarea conchy lifera semifossilis reperitur. 



This Helix, which is peculiar to Porto Santo, has been 

 found hitherto only in a subfossil state, — it being rather 



