222 Merriam Descriptions of Five New Rodents. 



Microtus kadiacensis sp. nov. 



Type from Kadiak Island, Alaska. No. 65827, 9 a d. "U. S. Nat. Mus., 

 Biological Survey Coll. Collected Sept. 12, 1893, by B. J. Bretherton. 

 Original No. 213. 



General characters. Similar to M. sitkensis in color and general appear 

 ance, but much smaller, somewhat paler, and under parts white instead 

 of ochraceous buff; tail and ears rather short. 



Color. Upper parts uniform grizzled pale brownish with pale dull ful 

 vous suffusion, not conspicuously lined with black hairs; under parts 

 plumbeous, strongly washed with pure white; tail sharply bicolor, dusky 

 above, white beneath ; fore and hind feet grayish brown. 



Cranial and dental characters. Skull similar to that of AL sitkensis, but 

 very much smaller ; interparietal much more elongated transversely and 

 narrower ; audital bulke very much smaller and narrower ; postpalatal 

 pits deeper; teeth essentially as in sitkensis, but first lower molar with 

 only 2 completely closed loops on each side. 



Measurements. Type specimen, measured in flesh by collector: total 

 length, 141; tail vertebrae, 23 [probably 33] ; hind foot, 18 [probably 19 

 or 20]. Cranial measurements : basal length, 23.5 ; zygomatic breadth, 13.5 ; 

 palatal length, 12.8; interorbital constriction, 3.8. 



Microtus unalascensis sp. nov. 



Type from Unalaska, Alaska. No. f |?|, $ im. U. S. Nat. Mus., Bio 

 logical Survey Coll. Collected Aug. 13, 1S91, by C. Hart Merriam. Orig 

 inal No. z. 



General characters. Similar to M. kadiacensis, but apparently somewhat 

 darker ; audital bullse much shorter and more globular ; front lower 

 molar with two closed and two open loops on inner side, and two closed 

 and no open loops on outer side. 



Color. (Specimen immature) : Upper parts yellowish brown, darkest 

 on head ; under parts plumbeous washed with whitish ; tail sharply bi 

 color, narrowly black above, broadly white below ; fore and hind feet 

 grayish. 



Measurements. Type specimen (not full grown) : total length, 122; tail 

 vertebrae, 28 ; hind foot, 19. 



Remarks. This species, which resembles M. mtticeps of Europe in the 

 enamel pattern of the first lower molar, is closely related to M. kadicfn- 

 sis, from which it may be distinguished at a glance by the much shorter 

 and more globular audital bullre and the pattern of TT. 



During the single night spent at Unalaska on my return from the Seal 

 Islands, I caught several of these Voles along the edges of a small pond 

 on the outskirts of the Aleutian village of Iluliuk. Unfortunately, all 

 but one were eaten by Ravens shortly after daylight. The one secured 

 had dragged the trap into the water and drowned out of reach of the 

 Ravens. 



