PREFACE, vii 
POSTSCRIPT. 
I raxe the opportunity of a new edition of my Journal to 
correct a few errors. At page 83 I 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 (‘ 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 Iam not convinced by his remarks. M. Bravard believes 
that the whole enormous Pampean deposit is a sub-aérial 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 with 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, 1st, 1860. 
