120 PROCEEDINGS OF THE ACADEMY OF [1898. 



A SMALL COLLECTION OF MAMMALS FROM NORTH- 

 EASTERN CHINA. 



BY SAMUEL N. RHOADS. 



These notes are based on a collection of seventeen mammals 

 brought to Philadelphia by Messrs. George and J. Edward Farnum, 

 the product of a hunting trip in the Chinese and Mongolian terri- 

 tories northeast of Pekin with Dr. A. Donaldson Smith during May, 

 June, July and August, 1897. By the generos'ty of these three 

 gentlemen the Academy of Natural Sciences of Philadelphia comes 

 into possession of the greater part of the collection, thus adding 

 seven species new to its museum. An account of their trip is being 

 prepared for the Geographical Journal of London. 



1. Microtus (Microtias) mongolicus (Radde). 1 Mongolian Vole. 



Seven specimens, Nos. 4,590 to 4,596, from along the shores of the 

 Sungari River in Mongolia north of Petun, come near M. arvalis 

 Pallas as defined by Poliakoff, Lataste and G. S. Miller, Jr. From 

 their greater size and resemblance to Radde's plate of mongolicus, 

 both as regards external and cranial characters, as well as from their 

 geographic position, it appears best to consider them asmo?igolicus. 

 Externally the adult specimens resemble closely in size and color 

 very large M.pennsylvanicus taken at the same season (July 16th) 

 in the vicinity of Philadelphia. The pelage of mongolicus, however, 

 is more thin and coarse, indicating a habitat in a hot climate. In 

 the skull of an old male specimen the interorbital ridges have 

 coalesced on the frontal suture in a sharp elevated median ridge. 

 Comparing it with 31. pennsylvanicus of same age and sex their 

 greatest zygomatic width is about the same, but the length of the 

 mongolicus skull is about 4 millimeters greater and its interorbital 

 elevation above the alveolus of m. 1 is 2 mm. greater, showing a 

 relative length and depth of cranium quite remarkable in the genus 

 and nowhere approached in any American species known to me. 

 The molar series are correspondingly long and narrow. It is a true 

 member of the subgenus Microtus as defined by Miller. 2 The hind 



^eis. im Ost-Sibir., I, p. 194, pi. VII. 

 2 N. Amer. Fauna, No. 12, 1896. 



