VOL. XIV, PP. 23-25 APRIL 2, 1901 



PROCEEDINGS 



or THE 



BIOLOGICAL SOCIETY OF WASHINGTON 

 GENERAL NOTES. 



The subgenus Rhinosciurus of Trouessart.* 



In the 'Catalogus Mammalium' (p. 410) Trouessart unites the Sciurus 

 laticaudatus of Miiller and Schlegel and the 8. davidianus of A. Milne- 

 Edwards to form the subgenus Rhinosciurus\ placed at the end of the 

 genus Xerus. Material in the United States National Museum shows 

 that the two species are not congeneric, and that neither is closely re 

 lated to Xerus. The genus Rhinosciurus (type R. tupaioides Blyth^:) is 

 strikingly characterized by its greatly elongated, cylindric, Tupaia-like 

 skull and small, slender incisors. The lower incisors are set more nearly 

 in line with the mandibular ramus than in other squirrels, and the upper 

 incisors are so small that in a skull 50 mm. in basal length they scarcely 

 equal those in a skull of Sciuropterus volans only 27 mm. long. The 

 'Xerus' davidianus on the other hand has a skull practically identical 

 with that of the Chinese Eutamias senescens, though much larger. In 

 deed the agreement with Eutamias in both cranial and dental characters 

 appears to be complete. Externally, however, the animal resembles 

 Sciurus in its well-haired, bushy tail and in the absence of stripes on the 

 body. It also diverges from Eutamias in the direction of Sciurus in the 

 reduction of the capacity of the cheek pouches. As the animal can 

 therefore be properly referred to none of the recognized groups it may 

 be made the type of a new genus Sciurotamias. Gerrit 8. Miller, Jr. 



^Published here by permission of the Secretary of the Smithsonian 

 Institution. 



fFirst used by Gray in 1843 (List Mamm. Brit. Mus. p. 195) for a genus 

 with B. tupaioides from Singapore as the type. Both generic and specific 

 names are nomina nuda and must date from their earliest definition. 

 The former was properly published by Gray in 1867 (Am. and Mag. Nat. 

 Hist., 3d ser. XX, p. 286), the latter by Blyth in 1855 (Jour. Asiat. Soc. 

 Bengal, XXIV, p. 477) as 8c\iurus] tupaioides, type locality Malacca. 



JThe relationship of this animal to the Bornean Rhinosciurus laticau 

 datus given by Thomas (Proc. Zool. Soc. London, 1807, p. 933) as type 

 of the subgenus is not fully understood. 



3 BIOL. Soc. WASH. VOL. XIV, 1901. (23) 



