MADEIRAN GROUP. 121 



latter phasis of the shell was the one described by Sowerby (in 

 1824) as his H. nitidiuscula, and by Mr. Lowe (in 1831) as 

 liis H. lurida The fortner (or pallid) one I cannot help sus- 

 pecting- may be the H. Hartungi of Albers ; though as I have 

 not been able to procure a type of the latter for examination, I 

 must necessarily speak with some amount of reserve. 



In a subfossil condition the H. nitidiuscula is tolerably 

 common throughout many of the calcai'eous deposits of Porto 

 Santo. At the Zimbral d'Areia it was met with by Mr. Lowe 

 and myself (during May of 1855) in considerable profusion; 

 'and I may add that the pallid variety of the shell was equally 

 abundant in a living state on the same actual spot. From their 

 general size and contour, semifossilized examples might some- 

 times be confounded 'prima facie with those of the H depau- 

 perata ; but the peculiar conformation of their aperture 

 (resulting from the more vertical prolongation of the axis) will 

 always suffice, on a closer inspection, to separate them. 



(§ Irus, Lowe.) 



Helix laciniosa. 



Helix laciniosa, Loiue, Ann. Nat. Hist, ix (1852) 

 „ Pfeiff., Mon. Hel. iii. 151 (1853) 



„ „ Loive., Proc. Zool. Soc. Lond. 174 (1854) 



„ „ Alb., Mai. Mad. 33. t. 8. f. 16-19 (1854) 



„ „ Paiva, Mon. Moll. Mad. 5Q (1867) 



Habitat Desertam Borealem. et Desertam Grrandem ; in ilia 

 praecipue abundans. 



It is on the northern (or flat) Deserta that this curious little 

 Helix attains its maximum ; for although it is found likewise 

 towards the northern end of the Deserta Gfrande, it exists there 

 very sparingly, and with all the appearance of having been acci- 

 dentally introduced from the smaller island. On the latter, 

 however, although separated from the Deserta Grande by so 

 narrow a channel, it absolutely swarms, — occuring in clusters, 

 beneath the stones. It was first detected there, during June of 

 1848, by Mr. Leacock ; and it has subsequently been taken, on 

 several occasions, by Mr. Lowe, myself, and others.' 



The H. laciniosa (the greatest diameter of which is only 



' I take no notice of the Baron Paiva's additional liaMiat for this extremely 



local little species, — the Ilheo de Ferro, oil the NW. coast of Porto iSanto, 



because I feel satisfied that it must have been cited on evidence which is not 

 trustworthy. The loose and unsatisfactory manner in which the Baron's ma- 

 terial was brought to him, by mere paid collectors, and his own extreme 

 inaccuracy (which I have often had occasion to deplore) in mixing up his 

 specimens from ditferent islands, would fully account for an occasional mis- 

 take as regards his localities. 



