i9ll] Swarth: Alaska Expedition of 1909. 131 



At Thomas Bay many well-defined runways were seen in thick 

 growths of lupines, but they were apparently the work of but a 

 few individuals, for only three were secured. The only other 

 mainland point where the species was encountered was at Brad 

 field Canal, where two were trapped under logs in the woods. 



Very small juvenals were caught in the traps on Kuiu Island 

 at the end of April, and thereafter in varying numbers and of 

 all sizes at nearly every point where the species was encountered. 



Alaskan examples of this mouse are uniformly quite small 

 as compared with those from the type locality of the species, 

 Olympic ]\lountains, Washington, judging from the published 

 measurements of the latter. The specimens at hand from the 

 Kake Islands, Prince of Wales, and Dall islands are all of about 

 the same size, eleven adult males from Prince of Wales Island 

 averaging: length 188.2, tail 73, hind foot 21.2. Curiously enough 

 those from JMitkof Island appear to be a trifle smaller, although 

 they were taken nearer the mainland than any others from island 

 localities, and the mainland specimens are much the largest of 

 the series. The five adults at hand from Bradfield Canal ajid 

 Thomas Bay average: length 198, tail 78, hind foot 22.2. 



Microtus coronarius, new species. 

 Coronation Island Meadow-mouse. 



Type.— Female adult; no. 8721, Univ. Calif. Mus. Vert. Zool. ; 

 Egg Harbor, Coronation Island, Alaska; May 16, 1909; collected 

 by H. S. Swarth ; orig. no. 7487. 



Characters. — Similar to Microtus macrurus in coloration and 

 proportions but size very much greater throughout. 



Coloration. — Essentially like Alaskan examples of M. mac- 

 rurus, being perhaps a trifle grayer and less brown. Upper 

 parts generally dark Vandyke brown, this color somewhat dark- 

 ened and obscured by numerous overlying black hairs. Sides 

 and that portion of the head anterior to and below the eyes much 

 paler, nearer broccoli brown, this in turn changing rather 

 abruptly to the dark gray of the entire under surface. Feet pale 

 gray, almost white. Tail distinctly bicolor, upper surface darker 

 and less brown than the back, under surface whitish. 



