THE BILL 



21 



A bill is hooked ^ when the upper mandible is abruptly curved 

 over the lower. In such cases the mandible often has teeth 

 along its edge, and the word dentate ^^ is used ; if there are a 

 number of teeth of about equal size, the word serrate ^ is used. 

 Spatidate, or sjwon-shaped,^ indicates a bill much depressed as 

 well as widened at the end. Cultrate. or knife-shaped j-* indicates 

 a much compressed bill with sharp edges. Falcate, or scythe- 

 shaped, indicates a curved, cultrate one. In the crossbill, the 

 upper and lower mandibles are oppositehj falcate.^ The ducks, 

 geese, and a few other birds have a peculiar set of ridges just 

 within the edges of the mandibles, in certain cases looking 

 much like teeth ; they are called lamellce, and a bill that has 

 them, lamellate.-*^ 



Besides the foregoing general terms, applying more or less 

 to all bills, there are some special forms which have been given 

 names that are frequently used in descriptions of birds. These 

 need to be well fixed in mind. Conirostrcd indicates such a bill 

 as the English sparrow has, — stout at base, conical in form, 

 and with the gape so angulated as to bring the corners of the 

 mouth down. Conirostral bills are short ^ in the sparrows and 

 long-' in the orioles. The swallows, etc., have Jissirostral^ 

 bills. In this class of bills the culmen is very short, but the 

 gape is both wide and deep, — about as wide as the head and 

 so deep as to reach to the eyes. The creepers and the hum- 

 mingbirds have tenidrostraV^ bills. The tenuirostral bill is 

 slender, long, and has a rather short gape. The snipes have 

 longirostral'^ bills; the bill is elongated, nearly equal in size 

 throughout, and with the upper mandible grooved for the slit- 

 like nostrils. 



