422 



INSULAR FLOEAS AND FAUNAS WITH 



[Ch. XLI. 



terised by peculiar species, and the insular and adjoining con- 



same 



Mr 



Helix. Bulimus, Achatina^ &c.. from 



Madeiran archipelago, 44 of wliich. were new. He then 



common 



and, what was still more astonishing, only two were common 



and Porto Santo, divided by a 



Is of Madeira 

 miles wide. 



memoir 



his own further investigations, and those of Mr. WoUaston 

 and others, have augmented the list of species, and taught 

 us that some few of those before known had a wider range 

 than was at first supposed ; but notwithstanding these 

 additions to our knowledge, the general conclusions an- 

 nounced in 1834 hold good, or are even rendered more 

 striking. The instruction derived 



from 



Madeira 



assembla 



animal creation in the ISTewer 



Pliocene period. Some few of the fossil species are extinct, 

 but most of them are the same as those now inhabiting 

 Madeira and Porto Santo respectively ; consequently the two 

 ancient groups of shells are as dissimilar as are the two 

 recent ones. Prom this we learn that in the Newer Pliocene 

 period the two islands must have been disjoined, as they are 

 now. It is also clear that at that period neither island was 

 united with the continent of Europe ; for scarcely any of the 

 fossil species are European, and the absence of these confirms 

 the general opinion of naturalists that almost all the species 

 now living in this archipelago and common to the continent 

 have been introduced by man since the beginning of the 

 fifteenth century. During my short stay in Madeira there 

 was found in the earth of a single flower-pot in which a 

 garden plant had been sent from Lisbon no less than three 

 species of Portuguese Helices, showing us how unconsciously 

 the horticulturist is busied in alloying the purity of the 

 native fauna. Most of the European ^ells have been found 



r 



in the gardens of Funchal, from whicli principal town as 

 from £1 centre tliey radiate for greater or less distances. 



