small Mammals from Salta and Jujuy. 187 



at this latter place, like the previous Jujuy collection, all show 

 a Btrong relationship to the species of the middle highlands 

 of Bolivia, 500 miles further northwards, first made known 

 through the efforts of Mr. Perry O. Simons. 



The most interesting forms in the collection are the little 

 hare of the Vermejo, Sylvifagus b. gibsoni, the first occurrence 

 of the Leporidse in Argentina, and the new genus Hypsimys, 

 .1 :fii//-\\kr iii general appearance but differing from all 

 members of." the AJcodon group by its extreme hypsodontism. 



1. Mohssus rufus, Geoff. 



$ . 8. Manuel Elordi, Vermejo, 500 m. 

 Quite like Paraguayan specimens representing M. cas- 

 taneus, but whether that is quite the same as the Cayenne 

 M. rufus I am somewhat doubtful. Several specimens of 

 the latter obtained by Mr. Cherrie are among the blackest 

 of the group. 



2. Oryzomys sp. 



S . 4 ; ? . 2, 3, G. Manuel Elordi, Upper Vermejo. 



3. Oryzomys sp. 



t?. 13, 14, 32, 34, 45 ; ? . 9, 10, 27, 28, 41, 44. Leon, 

 Jujuy, 1500 m. 



These two species of Oryzomys are both of the difficult 

 flavescens group ; the Jujuy one is the larger of the two. 



4. Phyllotis darwini tucumanus, Thos. 



<? . 12, 16, 23, 36 ; ? . 15, 17, 18, 19, 20, 24, 29, 30, 35. 

 Leon, Jujuy. 



5. Graomys lockwoodi, sp. n. 



<J. 5. Manuel Elordi, Vermejo, Salta, alt. 500 m. 

 7th August, 1917. B.M. no. 18. 1. 1. 6. Type. 



Most nearly resembling the Bolivian G. domorum, with 

 which it agrees in size (though its feet are longer), general 

 colour, and the slaty bases to the hairs on the chest and 

 belly, those of the chin and throat only being white to their 

 bases. Tail sharply bicolor, blackish above, white below, 

 not so heavily haired as in the type of G. cachinus. 



Skull of about the same size as in G. domorum and 

 cachinus. but its bullae larger than in the former, smaller 

 than in the latter. 



Incisors turned backwards towards the throat more than 



13* 



