1911] Swarth: Alaska Expedition of 1909. 133 



Twenty-two specimens were secured (uos. 8714-873-i, 9120), 

 seventeen from Coronation, and five from W,arren Island, twenty- 

 one of these being preserved as skins, and one in alcohol. These 

 examples are quite uniform in every respect, and none exhibits 

 any marked divergence from the general type. One or two 

 have a greenish stain on the underparts, which is probably wholly 

 adventitious, possibly caused by some of the wet vegetation in 

 which they live. 



Fiber zibethicus spatulatus Osgood. Northw^est Muskrat. 



A small series of muskrats taken at Portage Cove, Revillagi- 

 gedo Island, are in many respects very similar to specimens at 

 hand from Yukatat Bay, Alaska, and I provisionally refer them 

 to this Alaskan race. Ten specimens of spatulatus from the 

 Yukon Valley are more reddish in color, and apparently smaller, 

 though there are no measurements with the skins. Compared 

 with examples of osoijoosoisis from northern Washington 

 these island muskrats are paler colored and smaller, with short 

 tails and proportionately large feet. The skulls are short, but 

 very heavy and massive, with wide spreading zygomatic arches. 

 The five specimens secured are quite uniform in size and color, 

 as well as in the appearance of the skulls. They measure as 

 follows : 



Revillagigedo Island was the only place during the entire 

 summer where muskrats were encountered. The meadows border- 



