PERCHING-BIRDS. 115 



Section B. ACROMYODL Singing-Birds (p. 107). 

 Family I. ATRicHORNiTHiDiE. Scrub-birds. 



Only two small Australian species of the genus Atrichornis (1801) [Case?].] 

 are included in this family, peculiar among Passerine birds in having 

 the clavicles (merry-tiiought) rudimentary. The wings are so small 

 that the powers of flight are limited, and they live among the dwarf- 

 ferns and dense thickets, where they are only to be detected by their 



loud note. 



Family II. Hirundinid^e. Swallows. 



This well-defined cosmopolitan family, formerly associated with the [Case 71,] 

 Swifts (Cypselidce) on account of their similarity in general appearance 

 and habit of hawking insects on the wing, are now recognised as 

 belonging to the Passerine Birds. The long powerful wings, feebly 

 developed feet, small flattened bill and wide gape are the most striking 

 external features, possessed in common with the Swifts ; but the latter 

 may always be distinguished by having 10 instead of 12 tail-feathers. 

 The anatomical difl'erences between the two families are many and 

 striking. Many of the Swallows bijeed in colonies, and two or even 

 three broods are reared in a season. About 116 species are recognised 

 and divided into two subfamilies — the Hirundininee , including the true 

 Swallows and Martins, and the Psalidoprocnince, or Rough-winged 

 Swallows (1815), in which the outer margin of the first flight-feather is 

 provided with hooked barbs. 



Of the former the Common Swallow [Hirundo rustled) (1808) is 

 typical, and one of the most familiar and beloved of our summer visitors. 

 It ranges north in summer over Europe and Asia, extending beyond 

 the Arctic Circle, and winters in South Africa and the Malay Peninsula. 

 Many other species are equally migratory, and traverse immense 

 distances on their periodical journeys. The Red-rumped Swallow 

 [H. rufula) (1808 a) has been recorded from Kent as an accidental 

 visitor. Two other well-known visitors to the British Islands are the 

 House-Martin (Chelidon urbica) (1802), which builds mud-nests under 

 the eaves of houses and on the ledges of cliff's, and is easily recognised 

 by its feathered toes; and the Sand-Martin (Cottle riparia) (1806), 

 which excavates a tunnel in a bank terminating in a nesting-chamber. 

 Both these birds lay pure white eggs, but those of the Swallow are 

 spotted with reddish-brown and lavender-grey. 



Family III. Muscicapidj!. Flycatchers. 



This somewhat vaguely defined family includes a very large number [Case 71.] 

 of insect-eating species peculiar to the Old World, and may generally be 



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