206 BULLETIN 57, UNITED STATES NATIONAL MUSEUM. 



Genus SCOTOZOUS Dobson. 



1875. fivotozoHH Dobson, Proc. Zool. .Sue. Loudon, p. 372. 

 1878. Scotozous Dobson, Catal. Chiropt. Brit. Mus., p. 243 (subgenus of 

 Yespcniyo). 



Type-species. — Scotozous dormeri Dobson. 



Geographic distribution. — India and northwestern Africa. 



Number of forms. — Four, Scotozous dormeri Dobson, S. ruppelii 

 Fischer ( = Vesperugo temminckii of Dobson), S. pulcher Dobson, 

 rind S. deserti (Thomas). 



Characters. — Like Pipistrellus, but with outer upper incisor very 

 minute, its acutely pointed tip not extending beyond cingulum of 

 inner. The small tooth lies external to the line between canine and 

 inner incisor, and the large tooth is separated from canine by a space 

 less than half its breadth. Premaxillary shortened proportionately 

 with reduction of incisors. Upper canine without secondary cusp. 

 Cheek teeth normal. 



Species examined. — Scotozous dormeri (Dobson), S. ruppelii 

 (Fischer), and S. deserti (Thomas). 



Remarks. — In Scotozous ruppelii the inner upper incisor is strongly 

 bicuspid (in dormeri it is simple) and the premaxillary is less 

 shortened. The small outer incisor is, however, exactly as in S. 

 dormeri. 



Genus IA Thomas. 

 1902. la Thomas, Ann. and Mag. Nat. Hist., 7th ser., X, p. 163, August, 1902. 



Type-species. — la io Thomas. 



Geographic distribution. — Southern Hupeh, China. 



Number of forms. — Only the type species has yet been discovered. 



Characters. — Similar to Scotozous, but differing in the form of the 

 outer incisor, the crown of which is flat, with well-developed cingulum 

 and barely indicated central elevation, and in the less development of 

 the mesostyle in m 1 and m 2 , this cusp barely extending outward 

 to line joining extremities of parastyle and metastyle, while in the 

 related genera it extends distinctly beyond. The size of the only 

 known species is much greater than in the members of the genus 

 Scotozous; greatest length of skull 27 mm. instead of about 14 mm. 



Species examined. — la io Thomas. 



Remarks. — The relationship of la to Scotozous is undoubtedly very 

 close, but the dental characters are perhaps sufficient to keep the 

 genera separate. The difference in aspect due to the great size of 

 la io is very striking. 



