BIRDS. 23 



of the mandible : tongue nearly as long as the bill : 

 toes 3, all pieced forwards. 



49. URIA. Bz7/ strong, slender, pointed; the upper man- 

 dible slightly bending towards the point, covered 

 with short feathers at the base : nostril* linear, in a 

 hollow at the base of the bill : tongue nearly as long 

 as the bill : toes 3, all placed forwards. 



50. COLYMBUS. Bill strong, straight, pointed; upper- 

 mandible longer, the edges of each turning inwards : 

 nostrils linear: tongue long, pointed, toothed each 

 side near the base : legs thin, flat : toes 4, the outer- 

 one longer; back-toe small, connected by a small 

 membrane to the inner-one : tail short, of 20 or more 

 feathers. 



51. STERNA. Bill straight, slender, pointed, a little 

 compressed : nostrils linear : tongue slender, pointed : 

 wings very long: toes 4, slender; the back-toe very 

 small, and unconnected with the rest: tail mostly 

 forked, 



52. LARUS. Bill strong, straight, bending down at the 

 point, with an angular prominence on the under part 

 'of the lower mandible : nostrils linear, broader on the 

 forepart, placed in the middle of the bill: tongue 

 slightly cloven : legs naked above the knees ; toes 4 ; 

 the back-toe small, unconnected. 



53. PROCELLARIA. Bill a little compressed, hooked at 

 the point : nostrils cylindrical, contained in a tube : 

 legs naked a little above the knees : toes 3 , placed 

 forwards, with a spur pointing downwards instead of 

 the back-toe. 



54. MERGUS. Bill slender, a little depressed, with a 

 crooked nail at the point; the edges of the mandibles 

 with sharp scrratures: nostrils small, somewhat ovate, 

 in the middle of the bill : toes 3 forward, the outer- 

 one longer, and one behind, furnished with a web. 



55. ANAS. Bill broad, depressed, obtuse, with a nail at 

 the point; the mandible edged with lamellate obtuse 

 serratures : nostrils ovate : tongue broad, obtuse, 

 fringed on the edges near the base : toes 3 forwards, 

 the middle-one longer, and one behind unconnected. 



56. PELECANUS. IM/long, straight, with a hooked nail 

 at the point : nostrils concealed in a furrow : face anil 

 gullet bare of feathers : tots 4, all webbed together* 



