142 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 69 



gradation with other forms has been shown." As Dr. Allen remarks, 

 specimens from Panama described by Alston ("1878, p. 669) and 

 referred by him to Sciurus rufoniger were doubtless some form of 

 Microschirus. These examples, collected by Enrique Arce in western 

 Panama, were later assigned by Alston (1879, p. 134) to Sciurus 

 chrysurus. Arce visited the Volcan de Chiriqui and Alston's descrip- 

 tion of the specimens applies fairly well to Microsciurus boquetensis. 

 A specimen in the Museum of Comparative Zoology labelled 

 " Panama, Gerrard, 1873," and probably collected by Arce at Boquete 

 seems clearly referable to this species. 



Specimens examined : Boquete, 1 (topotype) ; " Panama " (prob- 

 ably Boquete), 1. 



MICROSCIURUS ALFARI BROWNI Bangs 



Brown's Pygmy Squirrel 



Sciurus (Microsciurus) browni Bangs, Bull. Mus. Comp. Zool., Vol. 39, 

 No. 2, p. 24, April, 1902. Type from Bugaba, Chiriqui, Panama. 



Brown's pygmy squirrel is paler in general color and the under- 

 pays are grayer than in the allied forms, Microsciurus a. alfari of 

 Costa Rica and Microsciurus a. venustulus of the Canal Zone and 

 eastern Panama. The tail is edged with grayish white instead of 

 reddish as in M. a. venustulus. 



This diminutive squirrel is known only from low elevations on 

 the Pacific slope in the western part of the republic. Mr. Bangs in 

 his original account of the animal says : " Mr. Brown [ W. W. 

 Brown, Jr.,] found this little squirrel in the forest about Bogaba 

 [ = Bugaba] , at 600 feet altitude. It was rare and exceedingly hard 

 to get, on account of its small size and dull coloring, and only by 

 devoting much time and energy to the chase did he succeed in taking- 

 five specimens." 



Specimens examined : Bugaba, 5. 1 



MICROSCIURUS ALFARI VENUSTULUS Goldman 



Canal Zone Pygmy Squirrel 



[Plate 30, figs. 2, 20] 



Microsciurus alfari venustulus Goldman, Smiths. Misc. Coll., Vol. 56, No. 36, 

 p. 4, February 19, 1912. Type from Gatun, Canal Zone, Panama. 



The Canal Zone representative of the Microsciurus alfari group 

 of pygmy squirrels differs from M. a. alfari of Costa Rica in less 

 rufescent general coloration, and from its closely allied geographic 

 neighbor, M. a. browni of western Panama, in the darker tone of the 



1 Four in collection Mus. Comp. Zool. 



