T.> 1: Mr, O. riiomas on 



15. Ctenomi/s juris, sp. n. 



<J . 703, 706 ; ? . 702, 704, 705. El Cliaguaral, between 

 San Pedro and Villa Carolina. Alt. 500 ni. 



"In stony ground in ravines running down to the river." 

 —E. B. 



A small species like C./oc^i' externally, but with much 

 smaller bullas. 



Size small, about as in hergi, 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 t!ie belly; concolor with the belly in fochi. 

 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'. Bullae small and narrow, but smoothly filled out, not 

 com])res3ed ; markedly smaller than m fochi. 



Incisors rather more proodont than usual, the index-angle 

 about 108°, in the type of bergi 100°, in that oi fochi 94°. 



Dimensions of the type : — 



Head and body 177 mm.; tail 72; himl foot 20. 



Skull: median length 42; condylo-incisive length 423; 

 zygomatic breadth (anterior) 27; nasals 13'2 x 7'5 ; inter- 

 orbital breadth 10 ; breadth across brain-case 17 ; bimealal 

 breadth 27 ; palatilar length 19*7 ; dental length 25 ; up[ter 

 tooih-serics (crowns) tS'3. 



Ti/pe. Adult male. B.M. no. 20. 1. 7. IIG. Original 

 number 70fi. Collected 3rd August, 1^19. 



The smaller bullai and usually undarkened forehead will 

 readily distinguish this tuco-tuco from its nearest ally O. fochi 

 of Chumbicha, Catamarca. 



Sr. Budin has taken great pains in getting tuco-tuco^, 

 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. 



