POSTSCRIPT. 



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1 1 TAKE the opportunity of a new edition of my Journal 

 ' to correct a few errors. At page 92 1 have stated 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('*ObservacionesGeologicas,"i857), 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 whole enormous Pampean deposit is a sub-aerial forma- 

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

 doctrine. 



At page 374 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 punctatissima and 

 Pyrocephalus nanus ; and probably with the Otus gala- 

 pagoensis 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 376, as being, on the 

 authority of M. Bibron, the same with a Chilian species, 

 is stated by Dr. Gunter (Zoolog. Soc, Jan. 24th, 1859) to 

 be a peculiar species, not known to inhabit any other 

 country. 



Feb. \sl, i860. 



