Mammals from Central Cordoua. 241 



Skull with the general characters of the group; bullae 

 slightly larger tlian in E. g. domorum, conspicuously smalh'r 

 than in E. fj. cachina and E. q. chacoensis. Teeth very small, 

 much smaller, and especially narrower, than in any of the 

 allied forms (so far as such measurements can be taken, the 

 breadth of m^ in E. <). doviorum is 1*8 niillim. and in E. g. cen- 

 tralis 1*5 milliin.). Supraorbital ridges well marked, with 

 rudimentary postorbital priyections. Overhanging point of 

 anterior zygomatic plato well defined. 



I)imensions of the type : — 



Head and body 130 millim. ; tail 156; hind foot, s. u. 27, 

 c. u. 29; ear 20. 



Skull: greatest length 33"5 ; basilar length 26; greatest 

 breadth 17; length of nasals 14; interorbital breadth 5*4; 

 breadth of brain-case 13'5 ; palate length 14'7 ; diastema 8'5 ; 

 length of bulla 6; length of upper molar series 4*5. 



Type. Old female. B.M. no. 2. 2. 5. 13. Original 

 number 1691. Killed 23rd November, 1901. 



By its small bullai tiiis subspecies is at once separated 

 from all the members of the group except E. g. donwruni^ 

 while both from that and every other it is distinguished by 

 its diminutive molars. 



7. Eligmodontta callosa^ Rengg. 

 (J. 2ud December, 1901. 



8. Akodon variusj Thos. 

 ? . 30th November, 1901. 



9. Ctenomys Bergi^ sp. n. 



2 c?,l ?. 



Allad to C. mendocinus, Phil., but smaller and with a 

 brown forehead and muzzle. 



Size small, though larger than in C. Pundti, Nehr., and 

 C. talaruniy Thos. Fur soft and fine; hairs of back 13-14 

 millim. in length. General colour above glossy uniform 

 sandy fawn, rather paler on the sides. Under surface also 

 pale fawn, concolor with the sides, not patched with white; 

 the hairs everywhere slaty grey at base. Centre of face from 

 muzzle to between the ears dark glossy brown, conspicuously 

 different from the rest of the animal. No collar or ear- 

 markings. Cheeks and chin like sides of body. Upper sur- 

 face of hands and feet thinly haired, dull whitish. Tail with 

 an indistinct dorsal crest ; thinly haired, scarcely pencilled, 

 })ale fawn. 



