18 



NOBTH AMEKICAl^ FAUNA. 



[No. 36. 



I. Paler; sides of face grayish fulvescens (p. 43). 



II. Darker; sides of face ochraceous-buff. .intermedius (p. 47). 

 jj. Upperparts mainly blackish or brownish. 



h. Skull heavy; interpterygoid fossa broad. 



I. Paler (less ochraceous) intermedius (p. 47). 



IL Darker (more ochraceous) aurantius (p. 48). 



Ick. Skull light; interpterygoid fossa narrow catalinx (p. 40). 



Jih. Tail length less than 80 mm. 



i. Upperparts mainly deep ochraceous-buff longicaudus (p. 33). 



ii. Upperparts mainly light ochraceous-buff or brownish. 



j. Skull length more than 21.5 mm azteciLs (p. 30). 



jj. Skull length less than 21.5 mm. 



I. Tail longer; ear 12-13 mm megalotis (p. 26). 



Jck. Tail shorter; ear 10-11 mm dychei (p. 30). 



cc. Tail length less than 65 mm. 

 d. Upperparts mainly grayish or light buff, mixed with black. 

 e. Black dorsal stripe distinct; ears usually with blackish patches. 



/. Paler; skull heavier albescens (p. 22). 



ff. Darker; ekuU lighter griseus (p. 23). 



ee. No distinct dorsal stripe; ears without blackish patches. 



/. Darker and more ochraceous dychei (p. 30). 



ff. Paler and less ochraceous. 



g. Larger; skull broader megalotis (p. 26). 



gg. Smaller; skull narrower montanus (p. 24). 



dd. Upperparts mainly blackish or dark brown. 

 e. Upperparts Prout's brown. 



/. Ear from notch 8-9 mm impiger (p. 20). 



ff. Ear from notch 9-10 mm humulis (p. 19). 



ee. Upperparts sooty or with blackish stripe merriami (p. 21). 



aa. Outer wall of anteorbital foramen usually narrower than width of interpterygoid 

 fossa ;^ upper molars always with subsidiary enamel loops. 

 h. Skull length more than 25 mm. 



c. Upperparts tawny or ochraceous-tawny. 



d. Upperparts tawny tenuirostris (p. 78). 



dd. Upperparts ochraceous-tawny aureus (p. 78). 



cc. Upperparts mimimy-brown (Panama) creper (p. 79). 



lb. Skull length less than 25 mm. 

 c. Rostrum long and slender; braincase inflated. 



d. Darker; underparts (in adult) pinkish cinnamon microdon (p. 80). 



dd. Paler; underparts white albilabris (p. 80). 



cc. Rostrum short and broad; braincase not inflated. 

 d. Upperparts tawny or cinnamon-brown. 



e. Colors darker; skull smaller mexicanu^ (p. 70). 



ee. Colors paler; skull larger. 



/. Upperparts bright tawny cherrii (p. 73). 



JSI'. Upperparts dull tawny or brownish. 



g. Smaller; underparts white milleri (p. 74). 



gg. Larger; underparts buffy soderstromi (p. 75). 



dd. Upperparts pinkish cinnamon. 



e. Skull length less than 23 mm gracilis (p. 76). 



ee. Skull length more than 23 mm goldmani (p. 72). 



1 In gracilis of about equal widtli or slightly broader. 



