various Soutlt-Amer/ccai Mammals. 355 



of the greatest of all naturalists, whose connection with its 

 distinction has been related above. 



Cerdocyon mimax, sp. n. 



Externally quite like examples from the same locality of 

 C. thous brasiliensis, but the skull and teeth very markedly 

 larfjer. 



Colour quite as in brnsilienst's. Back of ears blackish, 

 a bufTy-brown area round their bases. Feet black, with a 

 slight greyisli mixture on the metapodials. 



Skull (of a female, as compared with two males) markedly 

 larger in all dimensions. Forehead more convex, the height 

 of the skull distinctly greater. j\Iedian area between masse- 

 teric fossie of the usual narrow urn-shape. 



Teeth larger throughout. Premolars longer and narrower, 

 the third longer than the second. Carnassial and molars all 

 larger than in brasiliensis (see measurements). 



Dimensions of the type (measured in the flesh) : — 



Head and body 755 mm. ; tail 305 ; hind foot 132 ; 

 ear 75. 



Skull : condylo-basal length 147"5 ; zygomatic breadth 80 ; 

 nasals on middle line 49; interorbital breadth 29; inter- 

 temporal breadth 33 ; postorbital process to deltoid ridge 69 ; 

 breadth of brain-case 49*5 ; palatal length 75. 



Teeth (those of a male brasiliensis in brackets) : diameter 

 of canine on cingulimi 6*5 (6"3) ; horizontal length of />' 4'6, 

 />2 7-9 (7-3), p3 9-5 (7-2), ;," on outer edge 15-2 (12-3); com- 

 bined length of 7n' and w^ 21 (18'2) ; greatest diameter o£ 

 m' 14-6 (13-6). 



Ilab. Chapada, Matto Grosso. Alt. 800 m. 



Type. Arlult female. B.M. no. 3. 7. 7. 39. Collected 

 15th October, 1902, by Alphonse liobcrt. Presented by 

 Mrs. Percy Sladen. 



Tlie uniformity in both external and cranial characters of 

 all the available specimens of Cerdocyon from Bahia soutli- 

 \\ards to Rio Grande do Su'l and inland to Matto Grosso is 

 extreme, these representing the names brasiliensis (1821), 

 azarce (1&2G), yuara.ca (1839), melampus (1843), melano- 

 stomus (1843), and riocjrandensis (1910). The skulls, 

 whether of male or female, are always within a few milli- 

 metres of 138 mm. in condylo-basal length, and the upper 

 carnassial is always about 12'5 mm. on its outer edge. 



Furthermore, there is little, if anything, to distinguish 

 this widely-spread Brazilian animal from the true Guianan 

 thous (17(J<)), but the available specimens of the latter are so 



^^ 



