TERNS AND NODDIES. 511 
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} to 12 inches. The broad-billed 
tern (S. ewrygnatha), 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 COMMONER 
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, differing 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. 





























































































































































































































































Noddies. 














The  remark- 
able birds known 
as skimmers, or scissor-bills, 
constitute a subfamily (Rhyn- 
chopine), 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 
BLACK SKIMMER. 1S freely movable. The single 
Skimmers. 










































































































































































