112 MANUAL OP THE MOLLUSCA. 



Helix 49 Pupa 7 Cistula 1 



Streptaxis 3 Clausilia 4 Bourciera I 



Bullmua 200 Cylindrella 1 Cyclotus 8 



Succinea 9 Vitrina 1 Adamsiella 1 



Tornatellina 1 Limax 1 Helicina 6 



Achatina 10 Choanopoma 2 Trochatella I 



Glandina 6 Cyclophorus 2 



The presence of several species of the old-world genera 

 Clausilia and Streptaxis — both wanting in North America — be- 

 comes a significant fact when taken in connection with the 

 affinities of the higher animals of South America and Africa. 

 These imply a land- way across the Atlantic (at some very remote 

 period), more direct than would be afibrded by the continent 

 which is believed to have united the boreal regions at the close 

 of the Miocene age.* 



Corbicula cuneata and 3 species of Cyrena are found in the 

 Orinoco and smaller rivers ; and the remarkable genus Miilleria^ 

 representing the African yStheria, inhabits the Rio Magdalena. 

 A species of Ancylus is recorded from Venezuela. 



Galapagos Islands (No. 35). 

 The fauna and flora of these islands are peculiar, but related to 

 tropical South America. The only known land-shells are 17 

 small and obscure species of Bulimus, of which the most remark- 

 able is B. achatinellinus. Some of them are peculiar to par- 

 ticular islands, like the birds and reptiles, viz. : — Chatham 

 Island 2, Charles Island 3, Jacob Island 2, James Island 1. 

 *' The Archipelago is a little world within itself, or rather a 

 satellite attached to America, whence it has derived a few stray 

 colonists, and has received the general character of its indigenous 

 productions." (Darwin's Journal, p. 377.) 



23. Brazilian Region. 



The ** region of Palms and Melastomas," extending from the 

 Amazon to the southern tropic, is one of the richest zoological 

 provinces. It includes Bolivia, and the largest portion of Peru, 

 all that lies to the east of the Andes. The greater part of the 

 region is mountainous and rainy and densely wooded, but inter- 

 sected by extensive plains {Llanos) y some grassy and fertile, 



* In Lieut. Maury's phj^sical map of the Atlantic, the contour of this fonner land is 

 partly shown by the 2,000 fathom line, extending beyond the Canaries and Madeira, 

 and sending out a promonotory to the Azores. Clausilite are found in Eocene strata ; 

 perhaps even in the coal measures (p. 295). Principal Dawson has recently described 

 Pupa from the coal measures of Nova Scotia, which may be the same shell alluded 

 to here. 



