84 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 69 



Subfamily CRICETINAE. Harvest Mice, Rice Rats, 

 Cotton Rats, etc. 



Genus REITHRODONTOMYS Giglioli 

 The harvest mice are among the smallest of the Muridae. They 

 are slender, long-tailed animals resembling very closely some of the 

 smaller species of Oryzomys, but easily distinguished by the distinct 

 longitudinal grooves in the upper incisors. 



Subgenus REITHRODONTOMYS Giglioli. 

 REITHRODONTOMYS AUSTRALIS AUSTRALIS Allen 



Irazu Harvest Mouse 



Reithrodontomys australis Allen, Bull, Atner. Mus. Nat. Hist., Vol. 7, p. 328, 

 November 8, 1895. Type from Volcan de Irazu, Costa Rica. 



Reithrodontomys australis vulcanius Bangs, Bull. Mus, Comp, Zool,, Vol. 39, 

 No, 2, p. 38, text figs, 16-17, April, 1902. Type from Volcan de Chiriqui, 

 Chiriqui, Panama (altitude 10,300 feet). 



The Irazu harvest mouse ranges from Costa Rica into western 

 Panama, Two specimens collected by W, W. Brown, Jr., at 4,000 

 feet, near Boquete on the southern slope of the Volcan de Chiriqui 

 have been noted by Bangs (1902, p, 37) who says : " These I have 

 compared with the type of R. australis from Volcan de Trazu, Costa 

 Rica, loaned by Dr. Allen. In color they exactly agree, except that 

 the upper surface of the feet is darker, more grayish — the feet being 

 whitish in the type. The skulls of the two Boquete specimens are 

 heavier throughout, especially the rostral part, and in this character 

 they are intermediate between true R. australis and the form de- 

 scribed below from the summit of the Volcan de Chiriqui." R. a. 

 vulcanius, the form referred to by Bangs, has been regarded by 

 Howell (1914, p. 62) as agreeing too closely for separation from 

 typical R. a. australis. Specimens from Boquete and from near the 

 summit of the volcano appear very different as indicated by Bangs, 

 but the differences are scarcely beyond the range of individual varia- 

 tion exhibited by a series of typical examples of R. a. australis. 

 Additional specimens from Panama are much needed in order to 

 determine the point satisfactorily. If the two forms are inseparable 

 R. a. australis has an altitudinal range of over 6,000 feet on the slope 

 of the Volcan de Chiriqui. 



R. a. australis belongs to the typical subgenus, Reithrodontomys, 

 which lacks the mesostyles and mesostylids present in the subgenus 

 Aporodon, the group including the other known forms of the region. 



Specimens examined : Boquete, 2.* 



* Collection Mus. Comp. Zool. 



