122 TEST ACE A ATLANTIC A. 



from about 4 to 4J lines) displays much the same type of 

 colouring as the broadly bifasciated state of the H. vulgata ; 

 nevertheless its two bands are usually very wide, and frequently 

 subconfluent, so as to cause nearly the whole upper surface 

 (except a few detached, transverse, irregular, somewhat line-like 

 but broken-up, white fragments, across the fasciae) to be dark 

 brown, the umbilical area alone showing a ground-hue of a 

 dusky yellowish- white. The character of its aperture, however, 

 which is comparatively circular, the peristome being raised and 

 continuous across the body-volution, throws it into a different 

 section from that species ; the entire shell is a little less globose 

 (or more lenticular) than the H. vulgata, the whorls are rather 

 prominent and subangular, and the whole surface is not only 

 roughly sculptured with very coarse and irregular transverse 

 curved subfluent costse, but more or less clothed, when the spe- 

 cimens are fresh and unrubbed, with small fragile membrane- 

 ous laciniae. 



Helix depauperata. 



Helix depauperata, Lowe, Cambr. Phil. S. Trans, iv. 51. 

 Pfeiff., Mon. Hel. i. 166 (1848) 



5, Lowe, Proc. Zool. Soc. Lond. 174 



(1854) 

 Alb., Mai. Mad. 32. t. 8. f. 9-12 



(1854) 

 Paiva, Mon. Moll. Mad. 57 (1867) 



Habitat Portum Sanctum, insulasque parvas adjacentas ; et 

 recens et semifossilis, vulgaris. 



This is one of the most general, and widely spread, of the 

 Helices of Porto Santo, to which island (and the immediately 

 adjacent rocks) it is peculiar, occurring abundantly both in a 

 recent and subfossil condition ; and it may be regarded perhaps 

 as the Porto-San tan representative of the H. squalida of 

 Madeira. 



The H. depauperata is a rather insignificant Helix, either 

 of a uniformly pale brown or of a dingy brownish-white, rather 

 rounded (but not globose) in outline, with a distinct umbilicus, 

 and with its surface (which is opake) very minutely and deli- 

 cately granulated, but at the same time much roughened with 

 coarse transverse folds, which are so exceedingly irregular and 

 subconfluent as to cause the shell to appear well-nigh submal- 

 leate. Its aperture is not quite so continuous as in the H. lad- 

 niosa, nevertheless its upper and lower portions are joined 

 across the body volution by a corneous lamina so conspicuous as 

 to make it appear almost circular. 



