194 Mr. O. Thomas on 
15. Ctenomys juris, sp. n. 
3. 703,706; 2. 702,704,705. El Chaguaral, between 
San Pedro and Villa Carolina. Alt. 500 m. 
“Tn stony ground in ravines running down to the river.” 
—E. B. 
A small species like C. focht externally, but with much 
smaller bullee. 
Size small, about as in bergi, fochi, and dorsalis. General 
colour usually quite uniform pale brown, nearest to ‘ sayal 
brown ” along the back, paler on the sides. Under surface 
washed with pale buffy varying towards whitish, the best- 
marked specimens near “ pinkish buff.’’ Middle line of face 
normally little darker than back, but in two out of five speci- 
mens there is a marked darkening on the top of the muzzle, 
as in fochi. Size of neck with a buffy or whitish half-collar 
extending up to the ear. Inner side of forearm whitish, 
lighter than the belly; concolor with the belly in /foehz. 
Hands and feet whitish. Tail dull buffy whitish, with a dark 
brown terminal crest. 
Skull with broad nasals, little narrowed posteriorly. Zygo- 
mata widely expanded, the anterior zygomatic breadth often 
greater than the posterior. Palatal notch to level of middle 
of m?, Bulle small and narrow, but smoothly filled out, not 
compressed ; markedly smaller than in fochi. 
Incisors rather more proodont than usual, the index-angle 
about 108°, in the type of bergi 100°, in that of fochi 94°. 
Dimensions of the type :— 
Head and body 177 mm.; tail 72; hind foot 29. 
Skull: median length 42; condylo-incisive length 42°3 ; 
zygomatic breadth (anterior) 27; nasals 13°2 x 7°5 ; inter- 
orbital breadth 10; breadth across brain-case 17 ; bimeatal 
breadth 27 ; palatilar length 19°7; dental length 25; upper 
tooth-series (crowns) 8:3. 
Type. Adult male. B.M. no. 20.1.7.116. Original 
number 706. Collected 3rd August, 1919. 
The smaller bulle and usually undarkened forehead will 
readily distinguish this tuco-tuco from its nearest ally C. fochi 
of Chumbicha, Catamarca. 
Sr. Budin has taken great pains in getting tuco-tucos, 
making excursions in various directions to obtain them, and 
is now rewarded by the discovery of two further new forms. 
None appear to be found at Villa Carolina, or very close to 
the town of Jujuy. 
