1878.] MR. E. R. ALSTON ON NEOTROPICAL SQUIRRELS. 65/ 



of American Squirrels in the Collection of the British Museum " ', 

 in which he recognized twenty -nine Neotropical species as being 

 represented in the national cabinet, nineteen of them being described 

 as new. Last year appeared Messrs. Coues and Allen's exhaustive 

 volume of 'Monographs of North-American Rodentia' 2 , in which 

 the Squirrels are discussed by the last-named zoologist, who includes 

 the South-x\meriean species in his scope. Having had access to 

 considerably larger series of specimens than were available to most 

 previous writers, Mr. Allen was led to reduce the number of valid 

 species of Neotropical Squirrels to ten, with two " subspecies," 

 namely : — ■ 



Sciurus carolinensis. Sciurus leucops. 



, var. yucatanensis. cestuans. 



collicEi. , var. rufo-niger. 



aureiyaster. tephrog aster. 



boothia. gerrardi. 



hypopyrrhus. variabilis. 



He further remarked that he thought that " on the whole the 

 number of species will, by future investigations, be further reduced 

 rather than increased," and that he had erred in recognizing too 

 many species rather than too few. 



No one who is acquainted with Mr. J. A. Allen's recent memoirs 

 on the geographical variation of species, needs to be reminded of 

 his breadth of view and extreme carefulness in comparison ; and in 

 the present monograph these qualities are as conspicuous as ever. 

 In it Mr. Allen has done a great service in reducing the complicated 

 synonymy of the South-American Squirrels to some order ; and if 

 some of his identifications prove to be erroneous, the fault lies in 

 the often totally insufficient or even misleading descriptions of 

 some previous writers. 



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 Sciuri. In these 

 collections I have also 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 re- 

 cognized by him. This study has led me to accept many of Mr. 

 Allen's identifications (some of which are sufficiently startling at 

 first sight), and in some instances to carry the reduction of species 

 still further ; but it has also enabled me to correct a few errors in 

 his synonymy, and to point out a few apparently valid species 

 with which he was not acquainted. 



Particularly rich in this group are the Paris and British Mu- 

 seums ; and the study of their long suites of specimens leads one 

 irresistibly to conclusions which must appear strange to those who 

 only know the extreme links of the chain. Among other things they 



1 Ann. & Mag. Nat. Hist, 3rd scr. xx. pp. 415-4::.!. 

 - Eep. U.S. Geol. Survey of Territories, vol. xi. 



