474 LARIN^. 



wings about two inches longer than the taih Bill yellow, 

 with an orange-red patch toward the end ; tarsi and toes 

 yellow ; plumage white ; the back and wings blackish-grey, 

 tinged with purple ; the quills tipped with white. 



3. Larus argentatus. Herring Gull. Bill two inches 

 and a fourth along the ridge, which is much decurved toward 

 the end, nine-twelfths high at the angle, which is prominent ; 

 tarsus two inches and a half long ; wings surpassing the tail 

 by an inch and a half. Plumage white ; back and wings 

 light bluish-grey; quills largely tipped with Avhite, the outer 

 six in part black, two of them with a large white spot toward 

 the end. 



4. Larus glauciis. Glaucous Gull. Bill two inches and 

 three-fourths along the ridge, which is moderately decurved 

 toward the end, ten-twelfths high at the angle, which is pro- 

 minent ; tarsus three inches long ; wings about an inch 

 shorter than the tail ; total length from twenty-six to thirty- 

 two inches. Plumage white ; back and wings light bluish- 

 grey ; quills all W'hite at the end. 



5. Larus leucopterus. JVJiite-winged Gull. Bill nearly 

 two inches along the ridge, which is moderately decurved 

 toward the end, eight-twelfths high at the angle, which is 

 little prominent ; tarsus two inches and a half long ; wings a 

 little longer than the tail ; total length from twenty to twenty- 

 five inches. Plumage white ; back and wings light bluish- 

 grey ; quills all white at the end. 



6. Larus canus. Green-hilled Gidl. Bill gi-cyish-green, 

 or greenish-yellow, an inch and a half along the ridge, Avhich 

 is gently decurved toward the end, five-twelfths high at the 

 angle, which is little prominent ; tarsus two inches long ; 

 wings surpassing the tail by two inches. Plumage white ; 

 back and Avings light bluish-grey ; the quills largely tipped 

 with white, the outer five in part black, two of them with a 

 large white spot toward the end. 



GENUS V. GAVIA. MEW. 



Bill rather long, or of moderate length, slender, much 

 compressed, slightly decurved at the end, acute ; upper man- 



