Vol. V] TAYLOR— NEW SUBGENUS OF PHENACOMYS J 53 



females that the dissection of the nest would. In fact, since 

 the males may be more active as foragers than the females, 

 there might even be a disproportion of males. 



(3) Family relations 



In each nest in which young were discovered there was one 

 inner nest cavity and one brood of young. This would seem 

 to indicate that only one family lives in each occupied nest. 

 Possible evidence to the contrary was the capture of two 

 seemingly adult males in a tree in which a nest was being 

 dissected. It is not certain, however, that both these mice 

 came from this nest. 



Wilder says that he has several times found the female 

 and young in a large nest, and the male in a small nest a few 

 feet higher in the same tree. After remarking upon the diffi- 

 culty he has had in finding males he suggests that it is possible 

 they live in nests separate from those of the females, in the 

 large trees, where their small nests would not be noticed, 

 while the females for the most part select smaller trees. 



Clay asserts that the male and female of a family do not 

 live in the same nest during the rearing of the young, although 

 it is probable that the males do seek the family nest there- 

 after. The small nest of the males would be likely, says he, 

 to be destroyed by storms, necessitating the building of a new 

 nest each season. On January 6, 1912, two adults were found 

 in one nest, the one secured being a female. Clay suggests 

 that the "escape" was a male, and that the incident would sup- 

 port the theory that the male and female live together during 

 the winter months. 



This most interesting suggestion of Wilder and Clay de- 

 serves further investigation. If it is in accord with the facts, 

 there would be furnished an additional reason for the prepon- 

 derance of females in our series; for the large family nests 

 would be much more likely to be dissected than the small nests 

 of the males. It seems to the writer that the evidence on this 

 point of the separate nests for the sexes is inconclusive. 



