CAPBIMULGIBJE : GOATSUCKERS. 447 



lower end of the metatarsus, corresponding to the reversed position of the fourth toe, 

 iind the upper part of the same bone is perforated by canals for flexor tendons. Tlie 

 basal phalanges of the toes are short. The wing has 10 primaries, and short 

 secondary coverts (contrary to the rule in Picarice) ; tlie tail 10 rectrices, soft and 

 rounded in lyngida and Picumnidce, rigid and acuminate in Picida, where also a 

 supplementary pair of spui'ious feathers is developed, making 12 in all. The nostrils 

 vary: they are large and of peculiar structure in lyngidce, usually covered with 

 antrorse plumules in the rest. The bill is straight or nearly so, hard and strong, 

 acute or truncate, the mandibles equal; the tongue is lumbriciftjrm, and very gener- 

 ally extensile to a remarkable degree, by a singular elongation of the bones and 

 muscles (figs. 73, 74). The structure of the bony palate is unique among birds ; it 

 is called saurognathous by Parker (see p. 173). The salivary glands have an 

 unusual development, in the typical species at any rate. The sternum is doubly- 

 notched behind. A very strongly-marked group ; in some respects it approaches the 

 Passerine birds more nearly than other Picarice do. 

 However impossible it is to define any such group as the conventional Picarice, and how- 

 ever difficult it may be to make three or any other small number of subdivisions, the very 

 diversity of tlie forms enables us to define the families with ease. The student can never be in 

 doubt to which (me of the six North American families his specimen belongs. 



3. Suborder CYPSELIPORMES : Cypselipobm Birds. 



Fissirostral [Caprimiilgidce, Cijpselidcs) oi' tenuirostral (Trochilida-) Picarice. Wings 

 lengthened in the distal joints, shortened in the proximal, with 10 fully-developed primaries ; 

 making an instrument of remarkable power. Feet never zygodactyle nor syndactyle ; small, 

 weak, scarcely fitted for progression ; hind toe often elevated or versatile ; front toes often 

 webbed at base, or with abnormal ratio of phalanges, or bcjth these modifications together 

 (figs. 40, 41). Tail of 10 rectrices. Palate Eegithognathous (p. 172). Sternum deep-keeled, 

 its posterior border usually entire, or doubly-notched or fenestrate. Syringeal muscles not more 

 than one pair. The oil-gland nude. No cceca in Cgpselidce and TrocMlidcE ; cceca present in 

 CaprimidgidiE. Anomalogonatous ; no ambiens nor accessory femoro-caudal muscle. 



Contains the 3 families named above, — Goatsuckers, Swifts, and Humming -birds. Not- 

 withstanding the peculiarities of the latter, especially their long slender bill, they are really more 

 nearly r(;lated to the fissirostral Swifts than these are to the fissirostral CapjrimvlgidcB, in essential 

 structural characters. 



21. Family CAPRIMULGID^ : Goatsuckers 



(So called from a traditional superstition). 

 Fissirostral Picariae. Head broad, flattened ; 

 neck inappreciable; eyes and ears large. Bill 

 extremely small in its horny portion, which is 

 depressed, and triangular when viewed from 

 above, but with enormous gape reaching be- 

 low the eye, and generally with liristles attain- 

 ing an extraordinary development. Nostrils 



Fig. 289. — Wliipponrwill, a setirostral Caprimul- basal, exposed, roundish, with a raised border, 

 giiio. (FronD Tenney, after Wilson.) ,. , , . . ^ , ,,.. 



sometimes prolonged into a tube. Wings 



more or less lengthened and pointed, deriving their sweep mainly from elongation of the distal 



joints and the feathers, the proximal segment being short ; of 10 primaries and more than 9 



secondaries; the latter not so extremely short as in Cypselidce. Tail variable in shape, of 10 



