MADEIEAN GROUP, 113 



Helix pisana, Mouss., Faun. Mai. des Can. 28 (1872) 

 Watson, Journ. de Conch. 222 (1876) 



Habitat Maderam, et Portum Sanctum ; in arenis calcareis 

 juxta mare hinc inde abundans. Etiam in strata semifossilifero 

 prope Canical parcissime occurrere a Barone de Paiva dicitur ; 

 sed, nisi fallor, vix vere semifossilis (tantum antiqua emortua 

 decorticata) reperitur. 



The common European H. pisana, Miill., which occurs 

 both in the Azorean and Canarian archipelagos (abounding also 

 in the latter, as well as at the Salvages, under two or three 

 additional aberrant phases), swarms in the sandy calcareous 

 district near Canifal in Madeira proper, as well as on the low 

 calcareous plains of Porto Santo; but it has not yet been 

 observed in the other islands of the Group. It is recorded by 

 the Baron Paiva to be found likewise (though rarely) in a sub- 

 fossil condition, both in Madeira and Porto Santo ; but, so far 

 as I am aware, it . has never yet occurred in a truly subfossil 

 state, and I strongly suspect that the Baron's specimens were 

 only bleached and decorticated ones, such as have often been 

 obtained by Mr. Lowe and myself, in both islands, and which 

 had all the prima facie appearance of being semifossilized, 

 though a closer inspection invariably proved them to be but 

 faded and worn examples densely filled-up with drifted sand. 



The H. pisana goes through, in the Madeiran Group, the 

 usual amount of changes, both in colour and outline ; but on 

 the whole it is normal in its character, and has shaped out no 

 decided 'varieties' (properly so called), such as the geminata, 

 Mouss., and Grosseti, Tarnier, which manifest themselves at the 

 Canaries. 



( XeropUla, Held.) 



Helix caperata, 



Helix caperata, Mont., Test. Brit. 430. pi. 11. f. 11 (1803) 

 striata, Drop., Hist. Nat des Moll. 106. pi. 6. f. 18, 



19 (1805) 

 ? lauta, Lowe, Cambr. Phil. S. Trans. 53. t. 6. f . 9 



(1831) 

 caperata, Pfei/., Mon. Hel. i. 167 (1848) 



Habitat Portum Sanctum, rariss. ; inter Helices varias in 

 Portu Sancto certissime collectas, duo specimina (vix adulta, 

 sed sine dubio cum H. caperata, Mont., congruentia), unum sc. 

 nuper sed alterum in 1863, detexi. 



Two undoubted examples of this common Helix of more 

 northern latitudes have been detected by myself ( one of them 

 quite recently, and the other in 1863) amongst some miscel- 



