MADEIRAN GROUP. 123 



Helix squalida. 



Helix squalida, Lowe, Ann. Nat. Hist. ix. (1852) 

 „ „ Pfeiff., Mon. Hel. iii. 133 (1853) 



„ ., Lowe, Proc. Zool. Soc. Loud. 174 (1854) 



„ „ Alb., Mai. Mad. 33. t. 8. f. 13-15 (1854) 



„ „ Paiva, Mon. Moll. Mad. 58 (1867) 



Habitat Macleram; ad rapes excelsas umbrosas, interdum 

 etiam maritimas, seepe in terra quasi sepulta, rarissima. In 

 statu semifossili ad Canical abundat. 



The H. squalida, although abundant in a subfossil condition 

 at Canical, is one of the rarest of the recent species of Madeira 

 proper, — to which island it seems to be peculiar. Nevertheless 

 in distant places along the northern coast (as, for instance, 

 between Kibeira da Janella and Porto Moniz, and near Sao 

 Vicente and Seissal) it has been met with, both by Mr. Lowe 

 and myself, in tolerable numbers, — though more often dead and 

 decorticated, than living. I have likewise found it in the Kibeira 

 de Sta. Luzia, above Funchal ; and the Baron Paiva records it 

 at the Curral das Eomeiras.' l 



We may regard the H. squalida as representing in Madeira 

 proper the Porto-Santan H. depauperata. It is, however, a 

 little smaller than the latter, and with its spire more depressed 

 at the apex ; its volutions (which are equally opake) increase 

 more gradually (the ultimate and penultimate ones being nar- 

 rower, or less enlarged), its umbilicus is relatively wider and 

 more spiral or open, its colour generally is of a darker coffee- 

 brown, and the granulations of its entire surface (although 

 beautifully expressed) are both very much more minute and 

 more densely packed together. 2 The mode of life, too, of the 

 H. squalida, is different from that of the depauperata ; and it 

 has a singular habit (like the H. obtecta in Porto Santo, and 

 the H. latens in Madeira) of coating itself with a thick mass of 

 earth, or hardened mud, — which often makes it difficult to 

 detect amongst the loose dry rubble, and fine vegetable mould, 



1 The Baron Paiva cites the II. squalida, as occuring also, at any rate in a 

 subfossil state, in Porto Santo ; but I think that we must obtain better evi- 

 dence than this before we regard the species as extra-Madeiran,— for its 

 Porto-Santan analogue is clearly the H. depauperata., and (as I have already 

 mentioned) the Baron's material was so hastily and inaccurately brought to- 

 gether that his habitat-islands were often (to my own certain knowledge) 

 sadly mixed-up and confused. 



2 Although nothing could possibly be more constant, and elegant, than 

 this well-detined sculpture of the H. squalida, which is quite appreciable 

 under an ordinarily powerful lens, Dr. Albers appeared quite as unable to see 

 it as he was that of the H. nitidiusaula, — for he absolutely described the 

 surface as ' egranulata ! ' 



