34 BULLETIN NO. VII. 
the pelage being plumbeous at the base. Below, either grayish 
white or as above. On the head the hair is more lanuginous, 
extending nearly to the nose. The wing membrane is not 
furred. The skull is large, with a slight occipital crest; the 
orbital space is large. Dentition 7. 3, c. 4, m. 4x2—82. 
The first incisors above are much larger than the second and 
are irregularly bifid, the internal cusp being longest; canines 
large, with a minute basal cusp; first molar narrow. The six 
incisors of the lower jaw are crowded, tricuspidate. 'The two 
anterior molars (premolars) simple. 
I have no notes as to the abundance of this species. 
The following description will apply to a male captured early 
in June, and will illustrate the typical condition of the species 
in Minnesota: 
Total length, 4.1; tail to anus, 17.4; expanse, 12.70; radius, 
1.70; thumb, 0.25; first finger, 1.62; first phalanx second fin- 
ger, 1.69; first phalanx third finger, 1.58; first phalanx fourth 
finger, 1.50; tibia, 0.71; hight of ear medianly, 0.47; tragus, 
0.80; hight of ear externally from base of opening, 0.65; ear 
from nose, 0.70; eye from nose, 0.38; distance between nostrils, 
0.15; tail beyond web, 0.20. 
General color yellowish brown, inclining to chestnut; below 
lighter and more olivaceous; face, ears and web black, chin 
and throat dark. Webs scarcely at all hairy. Cheeks tumid, 
slightly warty; barbe fine, short; ears high, somewhat acute, 
convex on the front margin; tragus over one-third the height 
of ear, curved forward; basal lobe of ear of moderate size. 
Thumbs small. Tail exserted; soles with a callous at the heel. 
GENus LASIONYCTERIS. 
(=Vesperides, Coues. ) 
This genus is characterized by the dental formula 7. 4, ¢. }, 
m. +x2—86. Central upper incisors bicuspid. Skull rather 
flat, not crested. Thumb rather small. 
Lasionycteris noctivagans LECONTE, SP. 
SILVER-HAIRED BAT. 
Vespertilio noctivagans LECONTE. Cuvy. An. King., 1831. 
CooPER. Ann. Lye. N. Y., 1837. 
DEKAY. Nat. Hist. N. Y., 1842. 
WAGNER. Schreb. Siiug. 1855. 
Vespertilio auduboni HARLAN. Month. Am. Journ., 1831. 
