Vol. V] TAYLOR— NEIV SUBGENUS OF PHENACOMYS ' \^\ 



Still another colony was found in the Douglas firs imme- 

 diately south of Lierly's Ranch, four miles south of Mount 

 Sanhedrin, Mendocino County, California. One tree mouse 

 was here secured. 



At Mendocino City thirteen nests were carefully exam- 

 ined. In eight of these animals were actually found. In the 

 first colony there were about a dozen nests ; in that on the 

 side of the ravine, seven or eight. The colony north of 

 Hearst contained about the same number, while at Lierly's 

 there were more, although some of the nests observed in that 

 locality may have belonged exclusively to Sciurus griseus. 



4 OBSERVED MOVEMENTS 



Phenacomys longicaiidus does not seem to possess any ex- 

 traordinary agility, quickness, or aggressiveness of movement. 

 Wilder says the mice are quick to leave the nest when the 

 latter is disturbed, and remarks that while sometimes they 

 are caught in the nest they are more easily caught on the 

 ground, where, although not really slow, they are a little 

 clumsy. Shelton relates an instance where a tree mouse 

 left the nest just as the observer came on a level with the 

 structure. It ran out to the tip of a branch and was there 

 secured by means of a shot pistol. The same observer records 

 an instance of the frightening of a Phenacomys from its nest, 

 the animal showing remarkable agility, going from tip to tip 

 of the fir boughs with speed and ease, and so running from 

 tree to tree until finally it escaped into the branches of an 

 old cedar {Thuja plicata), the fourth tree from the nesting 

 site. This record of remarkable agility was not borne out by 

 our observations, according to which the animals ran rather 

 slowly and uncertainly along the twigs on which we saw them, 

 and seemed on the whole rather slow-moving. Several were 

 caught with the bare hands in the trees. One tree mouse, 

 which reached the ground, exhibited more speed there than 

 any we saw in the trees. It is quite possible, though on this 

 point there is no evidence, that Phenacomys longicaiidus is 

 strictly nocturnal and is bewildered by the light of day. 



The unwillingness of the tree mice to leave the nest was 

 quite evident. Ordinarily the occupants would remain until 

 much of the structure had been dissected away. In one 



