MYOTIS. 155 



length, 14.6; zygomatic width, 10 ; in tertemporal width, 4.1; breadth 

 of braincase, 7.8; length of upper tooth row, 6.1; length of mandible, 

 1 1. 6; length of lower tooth row, 6.2. Ex type in United States 

 National Museum. 



Myotis occultus Hollister. 



Myotis occultus Hollister, Proc. Biol. Soc, Wash., XXII, 1909, p. 43. 



Type locality. West side of Colorado River, 10 miles above Needles, 

 San Bernardino County, California. 



Genl. Char. Resembles M. peninsularis but smaller; torearm 

 shorter; tragus shorter, tip blunt. 



Color. Upperparts glossy Prout's-brown, tinged with cinnamon; 

 underparts paler, buff-tinged; ears and wings brown. Ex type in 

 United States National Museum. 



Measurements. Total length, 96; tail, 40; foot, 10.5; tibia, 14; 

 tragus, 6.5; thumb, -6. Skull: Total length, 15.3; zygomatic width, 

 9.5; intertemporal width, 4; length of upper, tooth row, 5.9; length of 

 mandible, n.8; length of lower tooth row, 5.8. Ex type in United 

 States National Museum. 



Myotis pernox Hollister. 



Myotis pernox Hollister, Smith. Misc. Coll., LVI, 1911, p. 4. 



Type locality. Henry House, Alberta. Canada. 



Genl. Char. Colors dark; braincase inflated. 



Color. Upperparts dark brown, under fur black; border around 

 base of interfemoral membrane burnt-umber; underparts dark drab- 

 brown; ears and membranes blackish. Ex type in United States 

 National Museum. 



Measurements. Total length, 88.5; tail, 39.5; foot, 9.5; forearm, 

 36.5; ear, 13; tragus, 6.7; thumb and claw, 5.7; tibia, 17. Skull: 

 Occipito-nasal length, 13.3; Hensel, 11.2; zygomatic width, 9.6; 

 intertemporal width, 4.4; width of braincase, 8; length of upper molar 

 series, 3.6; length of mandible, n; length of lower molar series, 5.3. 

 Ex type in United States National Museum. 



Myotis altifrons Hollister. 



Myotis altifrons Hollister, Smith. Misc. Coll., LVI, 1911, p. 3. 



Type locality. Henry House, Alberta, Canada. 



Genl. Char. Similar to M. lucifugus but foot larger. 



Color. Upperparts bistre, underparts dark Isabella color; ears and 

 membranes blackish. Ex type in United States National Museum. 



Measurements. Total length, 92; tail, 39; foot, n; forearm, 37; 

 ear, 12.5; tragus, 7.6; tibia, 16.7. Skull: Occipito-nasal length, 12.8; 



