203 
THE FAMILIES AND GENERA OF BATS. 
mass (in females 10 mm. long and 3 mm. wide) near middle of fore- 
arm. Skull (fig. 31) and teeth as in Myotis , but cingulum of lower 
canine forming a small cusp anteriorly and inner cusps of lower 
molars unusually well developed. 
Species examined . — Pizonyx vivesi (Menegaux). 
Remarks. — The size of the foot relatively to the tibia exceeds that 
in any of the large- footed species of Myotis , while the extreme com- 
pression of the claws is noticeably unlike any members of the related 
genus. The presence of the glandular masses in the wing is a char- 
acter unique in the family, though apparentlv analogous structures 
occur on the ear of Rhogeessa gracilis. 
Genus LASION YCTERIS Peters. 
1831. Vespertilio Le Conte, McMurtrie’s Cuvier, Anim. Kingd., I, p. 31 
(part). Not Vespertilio Linnaeus 1758. 
1864. Scotophilus H. Allen, Monogr. Bats N. Amer., p. 27, June, 1864 
(part). 
1865. Lasionycteris Peters, Monatsber. k. preuss. Akad. Wissensch., Ber- 
lin, p. 648. 
1870. Cneplialophilus Fitzinger, Sitzungsber. kais. Akad. Wissensch., Wien, 
Math.-N aturwissen'scb. Classe LXII, p. 8 (part). 
1875. Vesperides Coues, in Coues and Yarrow, Zoology of Wheeler’s Exped., 
p. 83. 
1878.* Lasionycteris Dobson, Catal. Cbiropt. Brit. Mus., p. 238 (subgenus of 
Vesperugo) . 
1894. Lasionycteris LI. Allen, Monogr. Bats N. Amer., 1893, p. 104, March 
14, 1894. 
1897. Lasionycteris Miller, North Amer. Fauna, No. 13, p. 85, October 16, 
1897. 
Type-species. — Vespertilio noctivagans Le Conte. 
Geographic distribution.— Northern North America south through 
the United States. 
Number of forms. — The type species only. 
Characters. — Dental formula : 
-2 3. 1.-2-4567 
12 3. 1. - 234567 
2-2 
3-3’ 
1-1 2-2 
1-1’ P m 3-3’ 
Structure of teeth as in Myotis / upper incisors of same general 
form and relative size, the inner strongly bicuspidate, the outer sim- 
ple; cheek teeth not peculiar except that pm 3 is absent, and the hypo- 
cone is distinctly indicated in first and second upper molars; third 
upper molar with more than half the crown area of first, its metacone 
nearly as large as paracone, and the three commissures well developed. 
Skull flattened, with broad rostrum, the depth of braincase including 
audital bullse about three- fourths mastoid breadth ; sagittal crest obso- 
lete; interorbital region wide, flattish, the upper edge of orbit with 
a low “ bead,” which near middle forms an angle suggesting an 
