Article II. DESCRIPTIONS OF TWO NEW SPECIES 

 OF SOUTH AMERICAN MURID^E. 



By J. A. ALLEN. 



For the material on which are based the descriptions of the 

 two species of South American Muridae here described I am in- 

 debted to the kindness of Mr. Oldfield Thomas, Curator of Mam- 

 mals in the British Museum, who in referring the specimens to 

 me for determination kindly gave me permission to publish any 

 species that proved to be new. He has also permitted me to re- 

 tain some of the duplicates for this Museum, the types being 

 very properly returned to the British Museum. 



Zygodontomys thomasi, 1 sp. nov. 



Type, ? ad., Campo Alegre, Venezuela, 90 miles south of Cumana (alt. 1625 

 feet), May 4, 1899. Collector's No. 416. Type in British Museum. 



Color above pale yellowish brown, clearest or most pronounced on the lower 

 back and rump, and slightly darkened with black-tipped hairs, especially over 

 the middle of the dorsal region ; paler and grayer on the sides ; sides of muzzle 

 pale yellowish ; below whitish gray, the hairs being plumbeous broadly tipped 

 with soiled white ; ears rather large, pale brown, clothed with fine short hairs ; 

 upper surface of both fore and hind feet pale buffy white, soles light brown, 

 palms flesh-color ; tail short, dark brown above, much lighter, grayish brown 

 beneath. 



Measurements'*. Type, head and body, 125 mm.; tail, 99 ; hind foot, 23; 

 ear, 18. Another specimen, $ ad., from Quebara Secca : Head and body, 

 ii 6 ; tail, 101 ; hind foot, 26 ; ear, 17. Another $ , young adult, from Campo 

 Alegre : Head and body, 113 ; tail, 100 ; hind foot, 25 ; ear, 17. 



Skull (type), occipital portion lacking, gives the following : Nasals to pos- 

 terior border of parietals, 27 ; nasals, 12 ; palatal length, 13.3 ; zygomatic 

 breadth, 16 ; interorbital breadth, 5 ; palatine foramina, 6.2 x 2.2 ; upper mo- 

 lar series, 4. 



This species is based on three specimens, collected at Campo 

 Alegre, Cumana, Venezuela, at altitudes varying from 1350 to 

 1625 feet, Feb. 2 and 7, and May 4, 1899, sent to me for exami- 

 nation by Mr. Oldfield Thomas, and on an additional specimen 

 (Am. Mus. No. 14731, 6 ad.), from a neighboring locality. In 

 general form and proportions it resembles Z. brevicauda (All. & 



1 Named for Mr. Oldfield Thomas, to whom I am indebted for valued assistance. 



2 Collector's measurements, from the fresh specimen. 



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