NO. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 243 



their smaller size, as gauged by the skull length. Professor Lonn- 

 berg's name racsilensis, from the plateau of Cacsile, Nunoa, quite 

 near La Raya Pass, is available for them. 



The broadly rounded choanal opening of the palate, so striking in 

 Lonnberg's figure of the type of cacsilensis, proves to be a character 

 quite untrustworthy. For while the guanaco usually has a narrow 

 V-shaped opening, and the vicugna a broad rounded one, the British 

 JSIuseum contains specimens forming exceptions to the rule in both 

 the species, and I therefore consider the type of cacsilensis to be 

 another such exception. 



In color there is less difference between cacsilensis and true huana- 

 chus than appears to be the case in the corresponding races of the 

 A'icugna. 



The type locality of huanachus may be taken as Quillota, Chile, the 

 only exact locality mentioned by Molina. In this region that author 

 states that during the winter the guanacos come down from the 

 mountains into the plains. 



Sexual difference in these animals is well marked in the sizes of 

 tlie incisors and canine teeth, so that skulls can be sexed at a glance. 



58. LAMA VICUGNA MENSALIS Thomas. 



1917. Lama vicugna mensalis Thomas, Smiths. Misc. Coll., vol. 68, No. 4, 

 p. 3. April 10, 1917. 



Size slightly less than in true vicugna and teeth much smaller. 

 Color more strongly fulvous. 



The tjpo. locality of Molina's Camelus vicugna should apparently 

 be taken as " the part, of the Chilean Cordillera facing the Prov- 

 inces of Coquimbo and Copiapo," and an example in the British 

 Museum from Catamarca may provisionally be said to represent tJiat 

 animal; for the chain of the Andes could be no barrier to a vicugna, 

 so that the forms of the eastern and western slopes would no doubt 

 be the same. 



From Peru and Bolivia quite a number of specimens are available, 

 and as compared with the Catamarca specimen these all agree in 

 having a slightly shorter skull, with shorter muzzle and nasal open- 

 ing, and much smaller teeth, the combined length of the upper molars 

 being usually well under 50 mm. (45 in the type, 44 and 45 in Lonn- 

 berg's two specimens), while the length in the Catamarca vicugna is 

 54 mm. The general color of the northern form is a strong cinna- 

 mon-tawny, the light underside white and sharply contrasted, while 

 in the specimen of true vicugna the color is a colder and more gray- 

 ish brown, somewhat like " avellaneous " of Ridgway. In this respect 

 Mr. Heller's specimen is less characteristic than usual, duller and 

 browner than in any others of the series of mensalis available. No 

 doubt therefore considerable variation will b© found to occur in the 



