38 



bulletin: museum of comparative zoology. 



Reithrodontomys australis vulcanius, subsp. no v. 



Type. — Mus. Comp. Zool., No. 10,281, ad. ^, Volcan de Chiriqui, May 26, 1901. 

 10,300 feet. 



Characters. — Pelage extremely long and silky ; colors much darker and 

 grayer than in true R. australis ; skull heavier, especially rostral portion ; 

 palatal slits longer and wider. 



Color. — Broad dorsal band strong sepia, paling off on sides to Isabella 

 color, somewhat shaded with cinnamon ; top of nose and head paler, grayer 

 than back ; under parts Isabella color, strongly shaded Avith cinnamon between 

 arms and about vent; feet and hands grayish; ears well haired, sepia (about 

 the same shade as darker parts of back) ; tail well clothed with short, close 

 hairs dusky above, grayish below. 



16. X 1| 



17. 



Figs. 16 and 17. Reithrodontomys australis vulcanius. Type. 



Measurements. — Type, adult ^, total length, 170; tail vertebrae, 95 ; hind 

 foot, 19; ear, 14. Skull, basal length, 19.4; occipitonasal length, 22.8; zygo- 

 matic width, 11.4; mastoid width, 11; interorbital width, 3.4; length of 

 nasals, 8.2 ; width of nasals, 2.6; length of palate to palatal notch, 9.2 ; length 

 of palatal slits, 5 ; width of palatal slits, 1.8; upper molar series, 3.2 ; length 

 of single half of mandible, 11.4. 



Remarks. — R. australis vulcanius is a well marked alpine form, very differ- 

 ent from true R- australis in color, and also in its exceedingly long, silky pelage. 

 The skull is slightly different. 



