12. TESPEETILIO. 285 



which thej' differ are so slight that it is very difficult to write in. 

 few words a description by which it may be possible to recngnise 

 with certainty a given species. 



Most of the species appear to be dwellers in woods, some (of the 

 subgenus Leuconoe especially) either habitually or occasionally live 

 in caves or under the roofs of houses. The position of attachment 

 of the wings to the hinder extremities and the size of the foot 

 appear to be connected with the nature of their dwelling-places, 

 the inhabitants of caves having larger feet more or less free from 

 the membranes, while those living in woods have much smaller feet 

 inclosed in the wing-membrane to the base of the toes. 



Compared with the species of Vesperugo, these Bats, as might be 

 expected from their more delicate organization, extend to a much 

 less degree into the colder latitudes, and in countries where the 

 species of both genera hibernate they leave their sleeping-places at 

 a much later period in the year. 



Synopsis of the Species. 



I. Feet very large ; wing-membrane from the tibia 

 or ankle, rarely from the side of the foot; 

 interfemoral membrane forming a very acute 

 angle in the centre of its free margin behind ; 

 tail projecting by the last vertebra or by the 

 last two vertebrte from the membrane ; cal- 

 caneum very long, extending at least three 

 fourths the distance between the ankle and the 



tail Subgen, Lkuconoe. 



u. Wings from the sides of the back near the spine. 

 a'. Wings from the middle of the tibiae ; the 

 second lower premolar minute, quite in- 

 ternal to the tooth-row. 



a. Trag^us short, straight, and obtusely 



pointed; frulong; forearm 2"'l .. 1. F. pj'/osMS, p. 280. 

 h'. Wings from the ankles ; the second lower 

 premolar in the tooth-row. 

 /3. Tragus moderately long, subacute ; [ p. 290. 



fur very short ; forearm 1"'8 2. V. macrotarsus, 



b. Wings from the sides of the body, 

 c'. Wings from the ankles, 

 c". The second lower premolar minute, quite 

 internal to the tooth-row. 

 y. Tragus straight ; fm* very short ; fore- 

 arm l"-6 3. F. hasseltii, p. 291. 



d". The second lower premolar stands in the 

 tooth-row, or, partially only, internal. 

 c'". The second upper premolar quite inter- 

 nal to the tooth-row. 

 8. Tragus straight ; fur moderately long ; [p. 292. 



forearm l"-55 4. V. adversus, 



d'"- The second upper premolar stands in 

 the tooth-row, or, with the first pre- 

 molar, is drawn partially inwards. 

 t. Tragus inclined outwards above, inner [p. 293. 



margin convex ; forearm 1 '''45 .... 6. V. capaccmii, 



