1915.] Allen, Review of the South American Sciuride. 153 
synonymy and 1 is considered indeterminable. Gray’s ‘Synopsis’ made 
endless trouble for his successors, the descriptions being in most cases in- 
adequate for the satisfactory identification of the species, and often the 
localities given are too indefinite for the requirements of modern zoology. 
The types of the new forms are fortunately still in the British Museum, and 
through these his species have been for the most part satisfactorily allo- 
cated. 
Doubtless Gray’s bad work helped to bring about the radical reaction on 
the species question, which reached its climax about ten or twelve years 
later, when, in 1877, the present writer published a revision of the American 
Sciuridee in Coues and Allen’s ‘Monographs of North American Rodentia,! 
in which all then known American Sciuride were included. Only 5 species 
were given positively as South American and one other (Sciurus nebouxi Eyd. 
& Sol.) provisionally. The number of South American specimens available 
for study numbered only 35, of which 15 were skins and 20 in alcohol. All 
of this material is again before me. The 20 alcoholic specimens and 7 of 
the skins were referred to Sciurus estuans, but none of them is referable to 
estuans as now restricted. Three other skins were referred to the Mexican 
S. hypopyrrhus Wagner, but they really represent S. stramineus, and one 
other skin referred to S. variabilis is referable to S. cgniventris. The four 
skins referred to S. gerrardi represent S. gerrardi choco Goldman of the 
present review. 
From the above statement it is evident that this 1877 revision of the 
South American Sciuride was based almost wholly on the literature of the 
subject, which was very fully cited, and discussed with considerable confi- 
dence, on the basis of what seemed:to be the conditions of variation in Cen- 
tral American and North American species, which for that early period were 
fairly well represented in the material available. 
The following year appeared Edward R. Alston’s paper ‘On the Squirrels 
of the Neotropical Region’ (Proc. Zool. Soe. London, June, 1898, pp. 656- 
670, pl. lxi), based on the collections in the museums of London, Paris, and 
Berlin. He says: ‘“ Within the last year I have been able to examine in the 
British Museum and the Museums of Berlin and Paris, the types of no less 
than forty-one nominal species of Neotropical Sciurz. In these collections 
I have been able to compare much more extensive series of specimens than 
even Mr. Allen had access to; and, through his kindness, I have examined 
typical examples of the species recognized by him. This study has led me 
to accept many of Mr. Allen’s identifications (some of which were sufficiently 
1 Monographs of North American Rodentia. Memoirs U. S. Geological and Geographi- 
cal Survey of the Territories (Hayden), Vol. IV, August, 1877. Sciuride, pp. 631-949. 
Species inhabiting Mexico, Central and South America, pp. 738-779. 
