PREFACE. vll 



rOSTSCRIPT. 



I take the opportunity of a new edition of my Journal to 

 correct a few errors. At page 83 I have slated that the 

 majority of the shells which were embedded with the extinct 

 mammals at Punta Alta, in Bahia Blanca, were still living 

 species. These shells have since been examined (see ' Geological 

 Observations in South America,' p. 83) by M. Alcide d'Orbigny, 

 and he pronounces them all to be recent. M. Aug. Bravard has 

 lately described, in a Spanish work (' Observaciones Geologicas,' 

 1857), this district, and he believes that the bones of the extinct 

 mammals were washed out of the underlying Pampean deposit, 

 and subsequently became embedded with the still existing shells ; 

 but I am not convinced by his remarks. M. Bravard believes 

 that the w r hole enormous Pampean deposit is a sub-aerial forma- 

 tion, like sand-dunes : this seems to me to be an untenable 

 doctrine. 



At page 378 I give a list of the birds inhabiting the Galapagos 

 Archipelago. The progress of research has shown that some of 

 these birds, which were then thought to be confined to the islands, 

 occur on the American continent. The eminent ornithologist, 

 Mr. Sclater, informs me that this is the case with the Strix puncta- 

 tissima and Pyrocephalus nanus; and probably witli the Otus 

 galapagoensis and Zenaida galapagoensis : so that the number of 

 endemic birds is reduced to twenty-three, or probably to twenty- 

 one. Mr. Sclater thinks that one or two of these endemic forms 

 should be ranked rather as varieties than species, which always 

 seemed to me probable. 



The snake mentioned at page 381, as being, on the authority 

 of M. Bibron, the same with a Chilian species, is stated by Dr. 

 Giinter (Zoolog. Soc, Jan. 24th, 1859) to be a peculiar species, 

 not known to inhabit any other country. 



Feb. Ut, 186C. 



