MANUAL OF NATURAL HISTORY. 47 



elevated and curved towards tip, nostrils 

 placed in a long groove, covered by a scale ; 

 lower part of tibiae sometimes bare; tarsi 

 generally lengthened, covered in front with 

 transverse scales; hind toe generally want- 

 ing, when present short and elevated ; back 

 much arched ; tail very short. 



8. Family. — Tringoid-Grouse (Thinocoridae). Bill 



short, rather broad at base, compressed to 

 tip, culmen curved to tip; nostrils fleshy; 

 wings long and pointed; tail short, rather 

 broad and rounded; tarsi short, strong, and 

 covered in front with transverse scales, or 

 wholly with reticulated scales, hind toe very 

 short. 



9. Family. — Sheathbills (Chionidae). Bill rather 



short, strong, compressed, base of upper man- 

 dible invested by a folded horny sheath 

 covering nostrils; orbits partly encircled by 

 a warty skin; wings rather long; tail of mo- 

 derate length and even; tarsi very strong 

 and covered with small rough scales. 



10. Family. — Tinamous (Tinamidae). Bill rather 



lengthened, not stout, slightly curved, some- 

 what depressed at base, which is covered by 

 a membrane, frontal feathers sometimes ad- 

 vancing to aperture of nostrils; wings short 

 and concave ; tarsi covered in front with 

 large scales; hind toe small or wanting; tail 

 rudimentary. 



