130 Mr. O. Thomas on 



2. Phyllotis ricardulus, Thos. 



<? . 410, 411, 420, 421, 457, 458, 473, 482 ; ? . 412, 456, 

 459, 463, 469, 479, 481, 483. Abrapampa, 3500 m. 



<? . 503, 506, 516, 517, 526, 535 ; ? . 502, 510, 525, 528, 

 543. Casabindo, 4000-4500 m. 



The Pericotes from Maimara, Jujuy, provisionally referred 

 to P. woljfsohni in 1913 *, appear also to be referable to 

 P. ricardulus, recently described from Otro Cerro, Catamarca. 



The true P. wolffsohni of Bolivia has decidedly larger 

 molars. 



3. Hesperomys carillus argunis, subsp. n. 



<J. 455, 477, 499, 500; ?. 496, 497. Abrapampa, 

 3500 m. 



" On the bank of the laguna, in humid pasture-land." 



Essential characters apparently quite as in the true H. ca- 

 rillus, but colour throughout much paler. General colour 

 above pale drabby buffy varying to greyish buffy ; sides 

 clearer, sometimes with a well-marked buffy line. Under 

 surface greyish white, the bases of the hairs broadly slaty. 

 Head like back. Ears with proectote brown lined with 

 buffy ; metentote strongly buffy ; a whitish postauricular 

 spot present. Hands and feet white. Tail wholly white, 

 one specimen only having its upper median line faintly 

 darkened. Mammce apparently 3 — 2 = 10. 



Skull apparently much as in carillus^ thougn he zygo- 

 matic plate is slightly broader than in our only example of 

 that animal. 



Dimensions o£ the type : — 



Head and body 79 mm. ; tail 45 ; hind foot 16'5 ; 

 ear 16*5. 



Skull : greatest length 22 ; condylo-incisive length 20*2 ; 

 zygomatic breadth 12 ; nasals 8'5 ; interorbital breadth 3*3 ; 

 palatilar length 9 - 2 ; palatal foramina 5 ; upper molar 

 series 3*4. 



Hab. as above. 



Type. Adult female. B.M. no. 19. 8. 1. 21. Original 

 number 496. Collected 17th February, 1919. 



This pretty laucha is evidently the dry-area representative 

 of the forest H. carillus, from which it differs by its con- 

 spicuously lighter colour. 



* Ann. & Mag. Nat. Hist. (3) xi. p. 139 (1913). 



