290 



HERONS, STORKS, AND IBISES 



majority of the group the hinder end of the mandible is truncated, this is 

 not the case with the ibises. Mostly birds of considerable size, 

 the members of this order all have long and powerful wings, 

 while in habits they are essentially waders and they generally 

 nest in trees. Externally, herons and storks present a marked 

 general similarity to cranes ; but, as we shall see in the sequel, 

 the latter differ in the structure of the palate, in their 

 "precocious" young, and also in the conformation of the 

 bones of the leg. In the cannon-bone the two outer trochlea} 

 are of nearly equal length. 



LOWER END OF THE LEFT 

 CANNON-BONE OF THE 

 INDIAN WOOD-STORK. 



The Heron Tribe. 



Family Ardeid^^. 



The members of this family have the body thin and much compressed, the 

 neck generally long and thin, and the beak straight, narrow, and pointed, with the 



grooves in which the nostrils are placed 

 stopping short of its extremity, and its 

 cutting- edges serrated at the tip.^ On 

 the chin the feathering generally or always 

 extends considerably in advance of the line 

 of the nostrils. The leg is of medium 

 length, with the front surface of the 

 metatarsus covered with more or less scute- 

 like plates, the toes are mostly three, and the 

 claw of the third one is pectinated on the 

 inner side. The wings, although large, are 

 somewhat blunt at the tip, owing to the 

 second, third, and fourth quills being nearly 

 equal in length. The short and rounded 

 tail has either ten or twelve feathers ; and 

 there are bare spaces round the eyes and 

 on the lores. The presence of a so-called 

 powder -down patch of crumbly downy 

 feathers on each side of the rump is 

 absolutely characteristic of the family ; and 

 there are no bare tracts on the sides of 

 the neck. The general plumage, which is very variable in colour, is soft and 

 loose; the feathers on the crown of the head, back, and upper breast being 

 frequently elongated. Externally the two sexes are chiefly distinguishable by 

 difference of size. In the skeleton the lower mandible is not produced posteriorly 

 to its articulation with the skull ; and the V-shaped furcula is characterised by 

 the projection of its median process within the angle, as shown in the figure. 

 With the exception of the extreme north, herons — of which there are some seventy 

 species — are met with in all parts of the globe, and at almost all habitable 



^ The boat-bill is exceptional in the form of the head and beak. 



FUBCTJLA OF HERON. 



