NO. 35 NEW MAMMALS — HOLLISTER 5 



Remarks. — A careful comparison of four skulls of adult caribou 

 from Manitoba and Keewatin with ten skulls from eastern Canada 

 and Maine, has convinced me that Richardson's sylvestris is a good 

 subspecies of the eastern Rangifcr caribou. I am indebted to Dr. 

 Glover M. Allen, of the Museum of Comparative Zoology, Cam- 

 bridge, Massachusetts, for the loan of several skulls of eastern cari- 

 bou, to supplement the National Museum series for this study. 



RANGIFER EXCELSIFRONS, sp. nov. 



Type from Meade River, near Point Barrow, Alaska. Cat. no. 

 16755, U. S. National Museum. Adult male, skull only. Collected 

 March, 1883, by Lieutenant P. H. Ray. Original no. 1496. 



Characters. — Skull short and broad. Compared with a large series 

 of skulls of Rangifer arcticus from Fort Anderson and Fort Rae, 

 Mackenzie, it is about the same average breadth across orbits, but 

 with rostrum considerably shorter. Braincase very high ; the frontal 

 bone abruptly rising, back of frontal depression, to a height of 35 

 millimeters above general plane of rostrum ; angle of profile of fore- 

 head from line of nasal bones and anterior portion of frontals is 

 about 45 degrees. The two branches of the parieto-frontal suture 

 meet to form the median frontal suture at the apex of this high 

 crown. Hollow between orbits deep and rounded. Teeth much as 

 in arcticus. Compared with all American mainland cariliou the 

 character of this high braincase is very distinctive. The skull of 

 Rangifcr gralandkus, however, exhibits much the same forehead 

 inflation, but the braincase in this species is very narrow, as opposed 

 to the broad braincase of R. e.vcclsifrons. The general shape of the 

 skull of excelsifrons is much like that of the Kamchatkan reindeer 

 but the size is very much less. 



Measurements of type .yy^i///.— Condylobasal length, 366 millimeters ; 

 basal length, 344; palatal length, 230; postpalatal length, 114; 

 greatest breadth, 175 ; greatest length of nasals, 1 19 ; maxillary tooth 

 row, crowns, 92.5 ; mandibular tooth row, 96 ; upper molars, 52 ; 

 upper premolars, 43 ; lower molars, 57.1 ; lower premolars, 42. 



Remarks.— \Niih a series of over eighty skulls of American main- 

 land caribou before me, I find no specimens of other forms approach- 

 ing R. e.vcclsifrons in the peculiar shape of the braincase. Compared 

 with a good series of skulls of R. stonei, the skull of R. excelsifrons 

 is very short and relatively broad. Skulls of old male stonei fre- 

 quently develop a longitudinal ridge on the forehead, which is very 

 dififerent from the general broad elevation of the crown of excelsi- 



