KEY TO THE FAMILIES OF BIRDS 47 



A. Head with a horny shield on the forehead ; i" in other respects fully 



feathered XLII. Rails, etc. 



A. Head with more or less of naked tracts (free from feathers but 

 usually with some hairs) in front of the eyes or around the 

 eyes ; ^^ ^~ some species have the head entirely naked. (H.) 

 A. Head fully feathered and without horny shield. (B. ) 

 B. Bill hard throughout and not sensitive (a peculiar smoothness of bill 



of dried specimens will show that the bill was hard in life). (E.) 

 B. Bill weak and soft, at least at base, often long and slender ; if short, 

 pigeon-like ; hind toe always less than half the length of the inner 

 one, sometimes absent ; (dried specimens usually show the surface of 

 the bills so roughened or dull in color as to indicate their soft condi- 

 tion when alive). (C.) 

 C. Toes with lobed membranes along their edges as wide as the toes, 

 sometimes wider ; ^^ tarsus much flattened sideways ; body flattened 



below XLI. Phalaropes. 



C. Legs exceedingly long, the tarsus over 31^ long. XL. Avocets, etc. 

 C. Tarsus less than Sh long ; toes with no wide membranes along their 

 edges. (D.) 

 D. Bill usually shorter than the head, pigeon-like, the soft base sepa- 

 rated by a narrow portion from the hard tip ; " toes only three (one 

 species has a hind toe ^ inch long) ; tarsus (reticulate) with rounded 



scales in front XXXVIIL Plovers. 



D. Bill slender ; nostrils narrow, exposed slits in elongated grooves ex- 

 tending from a half to nearly the full length of tlie bill ; i^ tarsus (scu- 



tellate) with transverse and more or less square scales in front 



XXXIX. Snipes, etc. 



E. Bill, 2|-8 long. (G.) 

 E. Bill, i-2f long. (F.) 

 F. Tarsus, middle toe and nail, and bill each about 1 long ; the bill 



nearly straight ; wing about 6 long XXXVII. Turnstones. 



F. Not as above ; tarsus usually shorter than the middle toe and nail ; 



if the tarsus is about 1 long, the wings are much less than 6 long 



XLII. Rails, etc. 



G. Bill nearly straight, much flattened sideways and very blunt at 



tip ; 18 toes only three and webbed at base. XXXVI. Oyster-catchers. 



G. Bill somewhat curved downward ; tarsus, 3^-6 long ; wing, 10-14 



long XLIII. Courlans. 



G. Bill about straight ; tarsus, 6-12 long ; wing, 16-25 long ; young : 

 XLI V. Cranes. 



