130 Mr. O. Thomas on 



2. Phyllotis ricardulus, Thos. 



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

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



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

 543. Casabindo, 4000-4500 m. 



The Pericotes from Maimara, Jujuy, provisionally referred 

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

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



The true P. icolffsohni of Bolivia has decidedly larger 

 molars. 



3. Ilesperomys carillus argurus, subsp. n. 



S. 455, 477, 499, 500; ?. 496, 497. Abrapampa, 

 3500 m. 



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



Essential characters apparently quite as in the true //. 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. Mammae apparently 3 — 2 = 10. 



Skull apparently much as in carillus, tliougn 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. 



Hob. 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). 



