1908.] Allen, The Peary Caribou. 489 



known caribou. In the Ellesmere Land specimens the pelage is less soft, 

 but in these the coat is thinner and more worn, as they were killed just 

 before the season of moult, which takes place in July. 



As shown by the subjoined table, 15 of the largest and oldest male skulls 

 of R. pearyi (all adult, with well-worn teeth) have an average total (condylo- 

 basal) length of 303 mm., ranging from 257 to 335 mm., the smallest being 

 one of the oldest of the series, with the teeth most worn. The same length 

 in a series of 7 old male R. arcticus is 363 (345-397) mm., and for 3 old 

 female skulls of arcticus 320 (303-337) mm., or considerably more than 

 the males of pearyi. Three male skulls of grcenlandicus average 368 (361 

 375) mm., or slightly more than the 7 skulls of arcticus, with slenderer, 

 less palmated, and more recurved antlers. 



In R. pearyi the main beam of the right antler in old males has an average 

 length of 1019 mm., the longest measuring 1205 and the shortest 826, with 

 4 above 1100 mm. and 3 below 900mm. In 7 R. arcticus the same average 

 measurement is 1200 mm. (1062-1505), and in R. grwlandicus 1141 (1063- 

 1246) mm. Thus the average in arcticus and groslandicus about equals 

 the maximum in pearyi. 



In R. pearyi the antlers have a much greater upward curvature than 

 in arcticus, in proportion to their length; those of the latter being remarka- 

 ble for their long, low, backward sweep and slight divergence, although 

 occasionally a specimen departs from this normal and approaches the 

 curvature and divergence seen in gramlandicus and pearyi. Figures 1-6 

 illustrate the types of antler seen in pearyi, and Figs. 7-10 the variation seen 

 in two fine heads of arcticus, one of which presents the unusual feature of 

 two large and equally developed brow antlers, one on each antler, directed 

 one above the other, thus avoiding contact. An average adult skull of the 

 female of R. pearyi is shown in Figs. 11 and 12. 



The inward curvature of the distal third of the main beam in R. pearyi 

 is especially marked, the distance between the tips being, in one third of the 

 specimens, less than 150 mm., and in one specimen (Figs. 11, 12) they actually 

 cross to the extent of 60 mm. The greatest spread (at point of palmation of 

 main antlers) equals about one half to two thirds the length of the main beam. 

 In 7 specimens the brow antler is developed from the right antler, in 8 others 

 from the left. The brow antler increases in size with the age of the animal, 

 being longest and broadest in very old animals and not well-developed in 

 males that have just fully acquired the permanent dentition. In general 

 the antlers are broader in all of their palmated parts, in proportion to their 

 size, than in either arcticus or grosnlandicus. 



A feature of interest in these skulls is the large amount of individual 

 variation. One male skull, and also one female skull, has two well-devel- 

 oped canines on the same side, both of normal size, the supernumerary 



