27(3 



NATURAL niSTORY COLLECTIONS IN ALASKA. 



as a delicac}-. Wbeu boiled tbese roots Lave much of the taste of a boiled unripe sweet potato, 

 and are very pleasing to the palate after the long abstinence from fresh vegetables one necessarily 

 undergoes while living in the north. 



During the winters when the snow remains on the ground from fall until spring compara- 

 tively few mice come about the houses until spring, when they are always numerous there. At 

 intervals there comes a winter in which, during December or January, there is a thaw, and melts 

 ofif all the snow. The water then percolates into all their burrows and storehouses, and the suc- 

 ceeding severe cold freezes everything solid for the remainder of the winter. This leaves the little 

 fellows without shelter or store with which to meet the remaining cold months. They are then 

 eaten by foxes and other animals, and many are frozen, while scores of them swarm about the 

 trading-posts and native villages. 



Their skins are used by the native children to make blankets and clothing for dolls, and the 

 little boys make toy traps in which they snare them just as their f Uhers take larger animals. 



These mice are omnivorous, and when two or more are confined in the same box the stronger 

 usually kill and partly devour the weaker ones the first night. 



The specimens of Arvicola from the vicinity of Saint Michaels were, as a rule, smaller aiul a 

 shade lighter colored than those from the Yukon region, and these peculiarities seemed to hold 

 good all along the coast of Bering Sea wherever I saw specimens. This difference was so marked 

 that I noted it in my field-book, and I am of the opinion that a careful comparison of specimens 

 w\U result in separating the meadow mouse of the barren coast region of Bering Sea and the Arctic 

 from that of the wooded interior and British America. 



In Mr. True's accompanying tabular arrangement of the specimens obtained by me he notes 

 this variation, and his "Series A" i-epresents the Bering Sea form, while the "Series B and C" 

 represent the common interior form, some of which are also found with the others along the coast; 

 but I did not see any examples of the small coast form from interior localities. 



Ea^otomyi^ RUTiLUf! (Pallas). Red-backed Mouse (Esk. Af-fslin-uk). 



Dr. Cones gives 3.33 inches as the average length of head and body in a series of sixty-seven 

 individuals of this species from Arctic regions. Sixteen skins in the collection under review give 

 iin average of 3.2 inches, which approximates very closely to the same. 



The average length of tail-vertebrie in Dr. Coues's series was "hard upon 1.10 inches." In 

 our series we determine it to be 1.05 inches. The largest skin has a length of 3.8 inches and the 



smallest of 2.8 inches. 



List of sjiecinu-iis. 



Biographical notes.— This is the prettiest species of mouse found in the north, and is common 

 and widelv distributed over nearly all of the Alaskan mainland. From the mouth of the Knsko- 

 quim north to Kotzebue Sound along the coast and throughout the interior it is everywhere nmii<r- 

 ous, as is attested by the specimens obtained by me and by the numbers of their skins 1 saw 

 among the native children during my sledge journeys. 



