308 BRITISH BIRDS. 



feathers. The hind toe, like that of most other Picarian birds, is much 

 shorter than any of the fore toes. 



There are about ninety species of Nightjars (Caprimulginse) and twenty 

 of Frog-mouths (Podarginae), so that the Family of Caprimulgidse, if it 

 really embraces both these groups, will contain about 110 species. The 

 Nightjars are cosmopolitan, except that they are absent from the Arctic 

 regions, and from the New Zealand and Polynesian Subregions of the 

 Australian Region. Three species only are found in Europe and North 

 Africa, one of which is a regular summer visitor to our islands, and the 

 other two are said to have visited us once. 



Genus CAPRIMULGUS. 



The genus Caprimulgus was recognized by Linnseus in the 12th edition 

 of his ' Systema Naturae/ i. p. 346, published in 1766. C. europaeus (the 

 Caprimulgus caprimulgus of Brisson) has been universally accepted as the 

 type. 



The species belonging to this genus may be distinguished from those 

 belonging to allied genera by having well-developed rictal bristles. In 

 other respects the differences are comparatively trifling. 



The genus contains about seventy species, about half of which belong to 

 the New World, and the remaining half to the Old World. They are only 

 absent from the Arctic regions, the Pacific Islands, and New Zealand. 

 Two species only breed in Europe, one of which is a regular summer 

 visitor to the British Islands, and the other has occurred once. A third 

 species, breeding in North-east Africa and South-west Asia, has on several 

 occasions strayed into Europe, and even wandered as far as this country. 



The Nightjars frequent open heaths, but are also found in wooded dis- 

 tricts. They are almost entirely nocturnal in their habits, and feed princi- 

 pally on insects, which they catch on the wing. They make no nest, but 

 deposit their eggs on the bare ground. Two is the usual number of their 

 eggs, which are much elongated, and almost as blunt at the small as at 

 the large end; they are dull white in colour, blotched and spotted with 

 brown or grey. 



