340 University of California Publications in Zoology. \Vou.5 
SkuLL.—Compared with skulls of orca from Cordova the 
series from Hawkins Island is somewhat wider zygomatically, 
which is due to the more spreading zygomatic arches, the two 
series averaging the same in leneth. Nasals slightly larger and 
somewhat longer. The two series of skulls differ most in the 
size of the audital bullae. These are conspicuously larger in 
the Hawkins series, their size difference being due chiefly to 
ereater inflation and depth of the bullae. 
M&ASUREMENTS.—Type: length 143 mm.; tail vertebrae 32; 
hind foot 19.5. Average of six adults from Canoe Passage, 
Hawkins Island: length 145; tail vertebrae 32; hind foot 19.5. 
Skull (type) : Hensel 22; zygomatic width 14.6; length of nasals 
7; diastema 8.8; alveolar length of upper molar series 5. Aver- 
age of six skulls from Canoe Passage, Hawkins Island: Hensel 
22; zygomatic width 14.4; leneth of nasals 7; diastema 7.7; 
alveolar length of upper molar series 5. 
The material in the collection representing .this new form 
consists of a series of ten adults from Canoe Passage, Hawkins 
Island, and five adults from Northeast Bay, Hinehinbrook Island. 
The small series from Hinchinbrook Island agrees well in 
coloration and skull characters with the Hawkins Island material. 
The whole series is very uniform in coloration and easily dis- 
tinguishable from the darker, dusky-tailed orca, which is a wide- 
spread form elsewhere in the Sound region. 
Microtus kadiacensis Merriam. Kadiak Vole. 
This is the most widespread species about the Sound. The 
series of 150 specimens represents twelve localities, as follows: 
Hawkins Island 14; Hinchinbrook Island 38; Chenega Island 
19; Grafton Island 5; Knight Island 7; Dise Island 7; Eleanor 
Island 4; Naked Island 9; Port Nell Juan 37; Valdez Narrows 
3; Thompson’s Pass 3; Cordova Bay 7. 
In size this series agrees better with Microtus kadiacensis 
than with MW. yakutatensis. There is, however, considerable local 
variation shown in some of the island material. Those speci- 
mens from Grafton Island are much darker, with darker wash 
over the underparts as in elymocetes, but they are much smaller 
than the latter species. The Naked Island series has shorter 
