INSESSORES. 463 



and the opening of the bill is fenced in by a number of bristles 

 (vibrissa). This arrangement is in accordance with the habits 

 of the Fissirostres, the typical members of which live upon 

 insects and take their prey upon the wing. The most typical 

 Fissirostral birds, in fact, such as the Swallows and Goat-suckers, 

 fly about with their mouths widely opened ; and the insects 

 which they catch in this way are prevented from escaping 

 partly by the bristles which border the gape, and partly by a 

 viscid saliva which covers the tongue and inside of the mouth. 



The typical Fissirostres, characterised by this structure of the 

 beak, comprise three families the Swallows and Martens 

 (Hirimdinidcz), the Swifts (Cypsdidce], and the Goat-suckers 

 (Caprimulgidce). These three families differ in many important 

 respects from one another, but it would be inconvenient to 

 separate them here. The Swifts, especially, are remarkable 

 for the peculiarity that whilst the hallux is present, it is turned 

 forwards along with the three anterior toes. The Goat-suckers, 

 again, hunt their prey by night, and they are provided with 

 the large eyes and thick soft plumage of all nocturnal birds. 

 Besides the above, there remain the two families of the King- 

 fishers and Bee-eaters, which are generally placed amongst the 

 Fissirostres, though in very many respects the arrangement 

 appears to be an unnatural one. These families are charac- 

 terised by their stronger and longer bills, and by having the 

 external toe nearly as long as the middle one, to which it is 

 united nearly as far as the penultimate joint. In consequence 

 of this peculiar conformation of the toes, these families were 

 united by Cuvier into a single group under the name of 

 Syndactyli. 



The Bee-eaters (Mcropida) live upon insects, chiefly upon 

 various species of bees and wasps ; but the King-fishers live 

 upon small fish, which they capture by dashing into the water. 

 The common King-fisher (Alcedo ispidd) is a somewhat rare 

 native of Britain, and is perhaps the most beautiful of all our 

 truly indigenous species. Some exotic King-fishers are of 

 large size, and one of the most remarkable of them is the 

 Laughing Jackass (Dacelo gigas) of Australia, so called from its 

 extraordinary song, resembling a prolonged hysterical laugh. 



