98 BIRDS OF ILLINOIS. 



Family GRUID-ffi— The Cranes. 



The diagnosis of this family has already been given on page 

 82. The species are all of very large size, and inhabit grassy 

 plains, as well as marshes. The bill is moderately long; the 

 nostrils broad and pervious, the nasal groove extending but 

 little beyond them. The legs are long, but the toes are short; 

 the hind toe is very short and much elevated, the claw scarcely 

 touching the ground. 



The genera are few in number, but one, Crrus, belonging to 

 North America. 



Genus GRUS Pallas. 



Grus Pall. Misc. Zool. 1766, 66. Type, Ardea grus Linn. 



Chak. Bill lengthened, straight, the upper mandible only slightly decurved at the ex- 

 treme tip ; the commissure and other outlines straight. Nasal groove very large and open, 

 extending over the basal two thirds of the bill. Nostrils broadly open, pervious ; the ante- 

 rior extremity half way from the tip of bill to eye. The upper half of the head naked, warty, 

 but with short hairs. 



Legs much lengthened; toes short, hardly more than one third the tarsus. Inner toe 

 rather longer, its claw much larger than the outer. Hind toe elevated, short. Toes con- 

 nected at base by membrane. Tarsi broadly scutellate anteriorly. Tertials longer than 

 primaries, decurved; first quill not much shorter than second. Tail of twelve feathers. 



Synopsis of Species. 



A. Adult plumage white, the primaries black ; cheeks naked. Bill very thick, the gonys 



strongly convex. 



1. G. americana. 



B. Adult plumage grayish or plumbeous, the primaries slate-color; cheeks always feath- 



ered. Bill slender, longer than middle toe ; gonys straight. 



2. G. canadensis. Wing, 17.75-19.00 inches ; culmen, 2. 90-3.70 ; tarsus, 6.70-8.00 ; middle toe 



2.80-2.95. Hah. Alaska to New Mexico and Texas, breeding (exclusively?) far 

 northward. 



3. G. mexicana. Wing, 22.00 inches; culmen, 5.00-6.00; tarsus, 10.00; middle toe, 3.50 or 



more. Hah. Western United States and Gulf States from Washington to 

 Florida. 



