590 Eepoet of State Geologist. 



b^. Tarsus marked with a network of lines over its whole surface ; meshes 

 slightly larger in front; its length not less than that of middle toe without 

 claw ; sexes alike. 



r' Cutting edge of upper mandible nearly 

 straight ; its serrations scarcely visible 

 from side, except near angle of mouth ; 

 head, bill and feet mostly black. 



Branta. 27 



r'. Cutting edge of upper mandible concave 



or sinuate; its serrations plainly visible 



from side for nearly its whole length; 



bill and feet pale. 



s'. Bill very stout; its depth at base more 



than half the length of upper mandible ; 



color largely white. Chen. 25 



s'. Bill smaller, more depressed; its depth 



at base not half the length of upper 



mandible; color not white. 



Anser. 26 

 a'. Neck as long as or longer than body; lores partly naked. 



Subfamily Cygnin^ Swaus. 

 i'. Color white; bill and feet black, in 

 adult ; grayish, head and neck brown- 

 ish ; bill and feet light, in young. 



Olob. 28 



Subfamily MERGIN^E. Mersansees. 



13. Gehus merganser Brisson. 



a'. Nostril nearer middle of bill than base. M. americanus (Cass.). 25 



a^. Nostril near base ef bill. M. serrator (Linn.). 26 



25. (129.) Merganser americanus (Cass.). 



American Merganser. 



Synonyms, Fish Duck, Goosakder. 



Nostrils situated near the middle of the upper mandible; frontal 

 feathers extending farther forward than those on lateral base of bill. 

 Adult Male. — Head and most of neck, greenish-black; head slightl}' 

 crested; chest and other lower parts, creamy white or pale salmon-color. 

 Adult Female. — Head and neck, reddish (chin and throat white), the 

 occiput with a full crest of lengthened feathers; above, chiefly bluish- 

 gray. 



Male; length, about 37.00; wing, 10.50-11.25; bill, 1.90-2.30; tarsus. 

 1.90-3.00. Female smaller. 



Kange. — North America generally. Breeds from latitude of Min- 

 nesota and Michigan northward; winters from Kansas, Indiana and 

 Maine southward. 



