678 AVES— TROPIC BIRD.. .DIVER. 



Edinburgh, where they are seen in the greatest abundance. " It is scarce- 

 ly possible to walk there without treading on them; the flocks of birds upon 

 the wing are so numerous as to darken the air like a cloud ; and their noise 

 is such, that one cannot, without difficulty, be heard by the person next to 

 him." 



THE TROPIC BIRD* 



Includes only three known species, which are all distinguished by a wedge- 

 like tail, the two middle feathers extending a vast length beyond the others 



THE COMMON TROPIC BIRD 2 



Is about the size of a widgeon. The length to the tip of the two long fea- 

 thers is nearly three feet. The bill is three inches long, and red ; the head, 

 neck, and under parts of the body, are quite white ; the upper parts of the 

 plumage white also, but marked with black lines. The two middle feathers 

 of the tail measure twenty inches, and project fifteen inches beyond the rest. 

 It takes its name from being chiefly found within the tropics. It frequently 

 flies very high, but generally attends upon the flying-fishes in their escape 

 from their watery enemies ; and they have now and then been found in calm 

 weather, supinely floating on the backs of the drowsy tortoises. Their flesh 

 is not good, but is sometimes eaten by the hungry sailors. 



THE GREAT NORTHERN DIVER* 



Is a very large bird, weighing sixteen pounds, and measuring three feet six 

 inches in length. The bill is strong, black, and above four inches in length. 



1 The genus Phaeton has the bill as long as the head, thick, stout, hard, sharp-edged, 

 much compressed, pointed, slightly sloped from the base ; edges of the mandibles widen- 

 ed at the base, compressed and serrated in the rest of their length ; nostrils basal, 

 lateral, covered above and near the base, by a naked membrane, and pervious ; legs very 

 short, placed far hack, all the toes connected by a web ; wings long; tail short, but the two 

 filamentous middle feathers very long. 



2 Phaeton pheenicurus, Lin. 



3 Cohprnbus glacialis, Lin. Tiie genus Colymbus has the bill of medium size, straight, 

 very pointed, compressed ; nostrils basal, lateral concave, oblong, half closed by a mem- 

 brane ; legs placed far behind ; tarsi compressed ; the three fore toes very long and 

 webbed; the hinder short, with a loose rudimentary web ; wings short; tail very short 

 and rounded. 



