1918] Grinnell: A Synopsis of the Bats of California 299 
In July, 1891, while one of the parties of the Death Valley Expedition was 
collecting at Old Fort Tejon, California, several species of bats were observed. 
The most abundant was a small Vespertilio [= Myotis|, which could be seen at 
dusk flying about the oak trees near the old barracks in great numbers, and 
passing in and out of the ruined buildings. A long two-story adobe building, 
with the roof still intact, seemed to be the center of attraction, and about sundown 
bats could be seen streaming forth from a window in one of the gables. On 
the morning of July 5 an examination was made of the attic of this building, 
and the bats were found clinging to the ridgepole and the rafters, literally by 
thousands. Individuals of all ages, from recently born young to adults, were 
hanging together in bunches as big as a bushel basket. Others found concealment 
in cracks and crevices, but very few were flying about. Evidently the colony 
had ocecupied.the attic for several years, but it was too dark to see whether more 
than one species was present. 
A sack was carried along under the ridgepole and specimens swept into it from 
several of the larger bunches. In this way more than a hundred bats were 
collected in a few minutes. As soon as they were disturbed they uttered a peculiar 
squeaking note and flew about in a confused manner in their efforts to escape. 
The sack was carried out under one of the oak trees and the specimens examined ; 
160 had been captured, and of these 25 were preserved! and the remainder allowed 
to escape. Some of the bats which had been given their liberty attempted to 
fly back to their retreat, but dazed by the sunlight took refuge in the branches 
of the nearest tree; others made no attempt to escape, except to crawl up the 
trunks of the trees, where they remained until dark. Some of the young ones 
failed to find their way back to the building, and remained about the spot for 
several days. 
In the summer of 1904 (July 19 to 26) J. Grinnell visited Fort 
Tejon and collected bats in the same locality visited by Dr. Palmer 
in 1891. Of the sixty-one examples of Myotis obtained on the later 
date not one proved to be Myotis thysanodes. 
Apparently bats of this species are not of wide distribution in 
California, for among nearly a thousand specimens of bats collected 
by the Museum of Vertebrate Zoology, only two have proven to be 
Myotis thysanodes. 
Genus Lasionycteris Peters 
This genus includes the type species only, which is distributed 
clear across northern North America and south nearly through the 
United States. 
Characters —Dental formula: i 72, e1!, pm22, m 22 = 36 
aracters.—Denta ; — ea 3-3 3-30 
SO Be atiqig © a) bilainy oe 
Upper incisors conical; inner upper incisor slightly the longer, 
and bicuspidate. Lower incisors subequal and crowded closely be- 
tween canines; crowns of inner lower incisors four-lobed, those of the 
outer lower incisors three-lobed. Canines both above and _ below 
1 Sixteen proved to be Myotis thysanodes; the others were M. yumanensis. 
