124 University of California Publications in Zoology. [Vol. 7 



measurements, mostly within the maximum of hylaeus. Speci- 

 mens from Bradfield Canal are of large size, but with rather 

 light skulls. Those from Etolin and Revillagigedo islands are 

 rather small, both externally and as to the skulls, but still much 

 larger than typical hylaeus. Five adults (nos. 8553-8557) col- 

 lected on Gravina Island, directly opposite Ketchikan, are 

 almost exactly intermediate between macrorhinus and hylaeus, 

 their measurements averaging : length 200.2, tail vertebrae 105.4, 

 hind foot, 23.8. The skulls are likewise of. an intermediate size. 

 Any one of these specimens, taken singly elsewhere, might be 

 referred to either of the two races, but on the whole, I believe 

 they belong with macrorhinus. They clearly do so on geograph- 

 ical grounds, and, though they vary in the direction of hylaeus, 

 there is no place where the ranges of the two races actually come 

 together in this part of Alaska. 



A single, imperfect specimen from Annette Island (no. 8552) 

 is, I believe, also referable to macrorhinus, though even smaller 

 (except its feet) than those from Gravina Island. In other 

 places, as at Bradfield Canal and northward along the coast, 

 intergradation appears to take place with hylaeus in varying 

 degrees as the range of that race is approached. 



On the whole the range of macrorhinus in Alaska may be 

 said to lie along the mainland coast and on the islands east of 

 Clarence Straits and Zarembo Island and, approximately, south 

 of the Stikine River. (See text figure 3, page 156.) 



Peromyscus maniculatus hylaeus Osgood. 

 Osgood White-footed Mouse. 



Ninety-two specimens of this mouse were taken, from 

 Kupreanof, Kuiu, Mitkof, Prince of Wales, Dall, Suemez, Heceta, 

 and Zarembo islands; and on the mainland at Thomas Bay, 

 Port Snettisham, and the Taku River (nos. 8471-8538, 8577-8591, 

 9129-9136). The Museum collection also contains a large series 

 from Admiralty Island, the form thus being represented from 

 almost all parts of its known range. 



Compared with Prince of Wales specimens, the mice from 

 the outlying western islands — Heceta, Suemez, and Dall islands 

 — have rather large feet, measuring from 23 to 25 millimeters. 



