Mammals from Jujuy. 191 
Size rather less than in true musculinus of Maimara, feet 
and tail averaging shorter. Colour above slightly duller, 
browner, and less clear, and below, where the difference is 
more noticeable, the tone is a dull pale drabby, approaching 
(though much less than) that found in JZus musculus, while 
in true musculinus the colour is a clear greyish white, with 
scarcely any suspicion of drabbiness. 
Dimensions of the type:— 
Head and body 94 mm.; tail 83; hind foot 19; 
ear 15. 
Skull: greatest length 24°5; condylo-incisive length 22°3 ; 
zygomatic breadth 13°4; nasals 9; interorbital breadth 3:8 ; 
palatilar length 10; palatal foramina 5-6; dental length 11; 
upper molar series 3:5. 
Hab. as above. 
Type. Adult male. B.M. no, 20.1.7.46. Original 
number 577. Collected 29th April, 1919. 
This laucha is no doubt very closely allied to the true 
musculinus * of Maimara, with which it shares the number of 
fourteen mammez; but on comparison of fifteen specimens 
with six of musculinus it proves to have so uniformly drabbier 
an under surface, while both feet and tail average shorter, 
that I have thought it worthy of having a distinctive name. 
A single old male skull—one of those overgrown examples 
which often render distinction by size so difficult—measures 
no less than 26 mm. in greatest length ; - but this is obviously 
abnormal, the type being of about the usual adult size. 
9. Oryzomys sp., flavescens group. 
3. 613, 614, 655, 663, 680; ¢. 624, 636, 639, 640, 648, 
Villa Carolina. 500 m. 
10. Graomys lockwoodi, Thos. 
3. 625, 631, 668, 681, 685, 694,697; 2. 616, 617, 644, 
672, 673, 689. Villa Carolina. 500 m. 
“Trapped among fallen trees.” ‘“‘ Lives in hollow tree- 
trunks.”—E. B. 
These specimens again show that the presence or absence 
of slate-grey at the bases of the belly-hairs is in this group 
a character of no importance, all conditions occurring in the 
series. 
None of these examples have feet quite as long as in the 
* Eligmodontia laucha musculina, Thos, Aun. & Mag. Nat. Hist. (8) 
xi, p. 188 (1913). 
