TERNS AND NODDIES. 



511 



COMMON TERN. 



Noddies. 



are large-sized forms belonging to a group of the genus in which the forehead is 

 black to the culmen of the beak ; whereas the sooty tern (*S^. fuliginosa) is the 

 British representative of another 

 group in which the front of the 

 forehead is white in the adult 

 plumage. From all the above the 

 lesser tern (>S^. minuta), together 

 with several other species, may be 

 distinguished by its inferior 

 dimensions ; the length of the wing 

 being less than 8 inches, whereas 

 in the other groups it varies from 

 9 1 to 12 inches. The broad-billed 

 tern (>S^. eurygnatha), of which the 

 head is figured on p. 510, is an 

 inhabitant of the Atlantic coast of 

 America, from South Brazil to the 

 island of Trinidad, and is repre- 

 sented by a closely allied species on 

 the Pacific coast of the New World. 



As an essentially tropical genus of the subfamily, brief mention 

 must be made of the noddies, typically represented by Anous 

 stolidus. These birds belong to a group of the subfamily, diflfering from the one 

 including the two last by the graduated tail, in which the feathers are pointed, 

 and the outermost shorter than the next pair. As a genus, the noddies are 

 characterised by the short middle toe, the strong decurved beak, and by the fourth 

 pair of tail-feathers, counting from the outer side, exceeding all the others in 

 length. The common noddy appears to be generally distributed throughout the 

 tropics, one of its best known breeding-haunts being the Tortuga Islands, off" 

 Florida. Its general colour is dark ; but, like the allied species, it has a light grey 



patch on the crown of the head 

 and forehead. 



The remark- 

 Skimmers. 



able birds known 



as skimmers, or scissor -bills, 

 constitute a subfamily (Rhyn- 

 chopince), distinguished not only 

 from the terns (which they other- 

 wise resemble), but likewise from 

 all other birds, by the peculiar 

 structure of the beak ; this organ 

 being elongated and compressed 

 to a knife -like form, with the 

 lower mandible considerably 

 longer than the upper one, which 

 is freely movable. The single 



BLACK SKIMMER. 



