0. VEBPEKOGO. 239 



nally, about one third shorter than the principal cusp ; the outer 

 incisor unicuspidate and equal in length to the outer cusp of the 

 inner incisor. Lower incisors very distinctly trifid, placed rather 

 across the direction of the jaws, but not crowded. The first upper 

 premolar minute and placed internally, but may be seen from with- 

 out, broad at the base and shortly conical ; the second premolar 

 longer than the succeeding molar ; last molar two thirds the size of 

 antepenultimate molar. First lower premolar small, but the second 

 is scarcely half its size and slightly internal to it ; the third premolar 

 exceeds the succeeding molar in vertical extent. 



Length (of an adult S , in spirits), head and body 2"-25, tail 1"'7, 

 head 0"-75, ear 0"-65, tragus 0"-28xO"-12, forearm l"-65, thumb 

 0"-22, third finger 2"-8, fifth finger l"-95, tibia 0"-7, foot 0"-3. 



This species is at once distinguished by the hairiness of the inter- 

 femoral membrane, and by the additional premolar in the lower jaw. 

 These differences, though very characteristic of the species, are not 

 sufficient to warrant its separation from Vesperugo, with the species 

 of which it otherwise presents in the aggregate of its natural cha- 

 racters close generic affinities. It may, however, be regarded as the 

 type of a subgenus, Lasionycteris, Ptrs. 



Hah. North America, from Hudson's Bay (James Bay) to Cali- 

 fornia, probably generally distributed between tbe 55th and 30th paral- 

 lels N. latitude. (See list of localities given by AHen, Z. c. p. 142.) 



This species has probably the highest northern range among the 

 Bats of America. 



a. ad. sk. Maiden, Canada. Dr. P. W. Maclagan [P.]. 



h. ad. 5 , al. Smithsonian Institute [P.]. 



c, ad. sk. No history. 



j„(, ?_^, p^, 1— i ; outer upper incisors very small, scarcely raised above 

 the gum, generally posterior to the tooth-row ; penis tvith a distinct 

 bone ; postcalcaneal lobe well developed ; tvingsfrom the base of the toes. 

 Hab. Oriental Region. Subgen. Hespeboptenus, Ptrs. 



Synopsis of the Species. 



a. Outer upper incisors in the tooth-row. 



d. Base of the thumbs simple, without adhe- 

 sive cushions ; forearm l"-4, tibia 0"-7.. 45. V. doricB, •^. 2m. 

 h. Outer upper incisors quite posterior to the 

 tooth-row. 

 b'. Base of the thumbs simple, without adhe- 

 sive cushions; forearm 2"-2, tibia 0"'9 . . 46. V. txckelh, p. 240. 

 c'. Base of the thumbs with broad adhesive ^ ^^ „ , ,. 



cushions; forearm 1"-1, tibia 0"-45 .... 47. V. Uanfordi, p. 242. 



45. Vespemgo dorise. 



Vesperus (Hesperoptenus) dorias, Peters, MB. Akad. Berl. 18G8, 

 p. 626. 



