70 ALLEN'S NATURALIST'S LIBRARY. 



the chamber was reached. In this particular instance the 

 tunnel and nest-chamber were quite clean, but these are some- 

 times in an extremely dirty condition, and Mr. Seebohm men- 

 tions that in one which he examined, "the bottom of the 

 passage was lined with a black or dark green glossy substance 

 smelling strongly of fish, and almost as sticky as bird-lime." 

 This is formed of the castings and droppings of the birds, and 

 the mass often swarms with maggots. The eggs are generally 

 laid upon a small heap of white fish-bones, cast up by the birds, 

 and this constitutes the whole of the " nest." 



Eggs. Six or seven, rarely eight or nine, in number. They 

 are pure white, very glossy, and nearly round. Axis, 0*95 inch ; 

 diam., 075 inch. 



THE ROLLERS. SUB-ORDER CORACLE. 



These birds constitute a group of Old- World Picarians, of 

 brilliant colour and somewhat Crow-like in form. They are 

 undoubtedly nearly allied to the Kingfishers and Bee-Eaters, 

 though they have not got the long bills of the two last-named 

 groups of birds. The palate is desmognathous, or " bridged," 

 and there are rudimentary basipterygoid processes, while the 

 breast-bone has four notches in its posterior margin. The 

 feet in the Rollers are very much like those of the Kingfishers, 

 that is to say, " Anisodactyle," the soles being flat and the toes 

 united together for a short distance by a membrane, the outer 

 one being joined to the middle one at the extreme base, and 

 to the inner one for the basal joint. The Family of Rollers is 

 divided into two Sub-families, the Ground Rollers (Brachy- 

 pteraciina) and the True Rollers (Coracitnce). The former 

 contains three ground-loving genera, all remarkable for their 

 very long legs, and confined to Madagascar, while the True 

 Rollers are found in the temperate and tropical portions of the 

 entire Old World. 



THE TRUE ROLLERS. FAMILY CORACIID^E. 



The species of Coraciidce at present known to us are but 

 twenty-one in number, and they are contained in two genera, 



