MAMMALS 267 



America {Vampyrus 5/'ec/rww) , whose horrid aspect has given it the 

 undeserved reputation of being a blood-sucker. The true blood- 

 sucking bats of South America are of small size and belong to the genera 

 Desmodus and Diphylla of this family. 



1. Mormoops Leach, Crown of head greatly elevated above face; 

 dentition 2/2, i/i, 2/3. ^/t,; nose-leaf absent: 2 species, i in the United 

 States. 



M. megalophylla senicula Rehn. Body brown in color; length 90 

 mm.; tail 28 mm.; forearm 56 mm.: southern Texas to Ecuador. 



2. Macrotus Gray. Dentition 2/2, i/i, 2/3, t^Jt,', head elongate; 

 nose-leaf simple: 4 species, i in the United States. 



M. californicus Baird (Fig. 148). Body pale brownish gray in 

 color; length 88 mm. ; tail ^2, mm. ; ears very large: arid regions of south- 

 western United States and of Mexico. 



3. Artibeus Leach. Dentition 2/2, i/i, 2/2, 2/3 or 2)ls\ nose-leaf 

 well developed; no external tail: 9 species, i in the United States. 



A. jamaicensis parvipes Rehn. Body brown or gray in color; 

 length 70 mm.; forearm 52 mm.: West Indias and Central America, 

 occasionally in Florida. 



Family 2. Vespertilionidae. — Mostly small bats with a large tragus 

 and a long tail which is either entirely or mostly enclosed in the inter- 

 femoral membrane; no nose-leaf; molars with distinct W-shaped cusps; 

 bony palate defective: 260 species, of cosmopolitan distribution, 

 including, with a few exceptions, all of the bats occurring in the United 

 States; 2 subfamilies. 



Key to the United States Subfamilies of Vespertilionidae 



El Lower incisors 6; snout without ridge i. Vesper tilionincB. 



a2 Lower incisors 4; horseshoe-shaped ridge on snout 2. Nyctophilin<z. 



Subfamily i. Vespertilionince. Bats with a simple snout and nos- 

 trils, with 6 lower incisors and ears usually not joined in front: over 20 

 American species. 



Key to the United States Genera of Vespertilioninae 



ai Ears not united in front. 



bi Upper incisors 4 (both sides) (Fig. 149). 



Ci Upper premolars 3 (on each side) (Fig. 149) i. Myotis. 



C2 Upper premolars 2. 



di Lower premolars 3 2 Lasionyctcris. 



do Lower premolars 2 3. Pipistrellus. 



C3 Upper premolars i 4. Epiesicus. 



ba Upper incisors 2 (both sides). 



