336 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
the ancestral stock was enabled to reach America from northeastern 
Asia by following land connections. In the particular accounts of the 
forms recognized in this paper, I have indicated more precisely the 
limits of distribution of each. 
Hapits. 
The Big-eared Bats are essentially cave-dwellers. In the West 
they frequently haunt the abandoned shafts and tunnels made by 
miners. Numbers of them may inhabit a single such tunnel, but they 
appear to rest singly, scattered along the rock walls, rather than in 
clusters. J. K. Townsend (1839) in the journal of his expedition to 
the Columbia River, Oregon, in 1834, relates that they often lived in 
the storehouses at the forts, and were considered by the fur traders to 
be beneficial in ridding such places of Dermestes. 
There is no evidence to indicate that any of the forms are migratory. 
In the northern part of their range they retire to suitable caverns to 
hibernate. Hahn (1909) records finding specimens in caves at 
Mitchell, Indiana, during the winter of 1906-7 and Butler (1895) 
obtained two from Greencastle, Ind., 23 December, 1894. Brimley 
(1905) reports one taken 1 February, 1893, in Bertie Co., North 
Carolina. The University of Colorado has two from Boulder County 
in that State, captured in mid-winter, one on 21 January, 1912, in a 
mine-tunnel where the temperature was 48° F., the other on 23 Febru- 
ary, 1910, in a tunnel at fifty feet from the surface (altitude 7760 feet). 
The young are probably born in early July or even earlier in the 
southern part of the range. Stephens (1906, p. 265) records a female 
of C. m. pallescens captured at San Diego, California, on 25 April, 
that contained a single foetus. In the San Jacinto Mts., of Southern 
California, Grinnell and Swarth (1913, p. 379) collected a female 
containing a single large foetus about 5 June. They found that the 
adult bats in a resting posture folded the long ears back against the 
sides, close to the body, a habit which Hahn (1909) seems to have been 
the first to record in the case of specimens from Indiana. In a 
freshly killed specimen, however, the ears project forward. 
History AND NOMENCLATURE. 
What is perhaps the first mention of a bat of this genus, is found in 
Clapton’s (1722, p. 594) account of the animals and other products of 
