536 CLASS xvi. 



third. Sp. Acanthyllis pelasgia, Hirundo pelasgla L., WlLS. Am. On. 

 1*1. 39, fig. i ; Acanthyllis collaris, Hirundo albicoltis VIEILL. Gal. PI. 

 120, PI. col. 195; Acanthyllis spinicauda, Cyp&elus spinicaudatus TEMM., 

 BUFF. PL enl 736, fig. i. 



Dendrochelidon BoiE (Macropterus s. Macropteryx SWAINS., 

 Pallestre LESS.). Three toes anterior ; hallux posterior. Tarsi in 

 some naked, in others hirsute. Wings very long, with first two 

 feathers subequal. Tail forked. 



Sp. a) Outer tail-feathers longer than wings. Bill depressed, flat, verj 

 broad at the base. Wings with first quill longest of all. Dendrochelidon 

 mystacina, Oypselus mystaceus LESS. Voy. Coquilk, Ois. PI. 22, Diet. univ. 

 ist. not., Ois. PI. 3, fig. i ; New Guinea. 



b) Point of wing produced beyond the outer tail-feathers. Bill with 

 culmen curved. 



s 



t Wings with first quill longest of all. 



Sp. Dendrochelidon comata, Cypselus comatus TEMM. PL col. 286 ; Sumatra, 

 Borneo. 



*H* Wings with second quill longest of all. 



Sp. Dendrochelidon longipennis, Hirundo Klecho HOBSF., TEMM., PI. col. 83 ; 

 Java, Sumatra, &c. 



Family LI. Nyctichelidones (Caprimulgidce BONAP., G-RAY). 

 Wings long, with ten primaries. Wing-coverts long. Plumage 

 lax, soft. Head broad, flat above. Bill curved, short; gape of 

 mouth large, descending below the eyes. Tarsi mostly short, strong, 

 scutellate anteriorly, often hirsute. Tail with ten feathers. 



A) With outer toe short (only four phalanges) ; with claw of middle toe 

 dilated internally, incised pectinately. 



Caprimulgus L. Bill very short, flexile, depressed at the base, 

 broad, compressed at the tip and bent into a round hook. Rigid 

 bristles, thick at the base, placed in a row along the upper margin 

 of gape, directed forwards. Nostrils basal, approximate, subtubu- 

 lar. Anterior toes conjoined at the base by membrane, outer toe 

 short, middle long, with claw pectinately incised. Hallux short, 

 versatile. Wings elongate, with second quill mostly the longest of 

 all.' Tail various in form, in several elongate. 



The goat-suckers. These nocturnal birds bear, according to the remark 

 of LINNAEUS, the same relation to the swallows that the owls do to the 



