BIRDS OF NORTH AND MIDDLE AMERICA. 683 



aa. Tarsus shorter than first digit; head with a crest or with mystacial or superciliary 

 plumes, flanks with a patch of downy or silky feathers, and general plumage 

 soft; rostral portion of cranium moderate; nasals forked, abutting against frontals; 

 ecto-ethmoid narrow; vomer scarcely expanded; palatines unnotched; meta- 

 sternum slightly concave, perforated by two foramina; ulna longer than second 

 metacarpal; phalanges not shortened; shoulder muscles passerine; deep plantar 

 tendons characteristic. (Indo-Malayan Subregion and Papuan portion of 

 Australian Region.) Dendrochelidonidse (extraliniital).o 



Family MICROPODID^. 



THE TRUE SWIFTS.') 



= Micropodldx Lucas, Auk, vi, 1889, 13. 



=Apodinae -{-Chaeturinae IIartert, Das Tierreich, Podarg., Caprim., Macropt., 



1897, 62, 63, 65, 80. 

 = Cypselid!i' Sharpe, Hand-list, ii, 1900, 89. 



Micropodii with the tarsus longer than the fu-st digit; head without 

 crest or plumes, flanks without downy or silky feathers, and general 

 plumage hard; rostral portion of cranium broad; nasal triradiate, 

 overlapping frontals; ecto-ethmoid wide; vomer T-shaped, much 

 expanded anteriorly; palatines notched anteriorly; metasternum 

 convex, usually entire (with foramina in Tachornis only ?) ; ulna 

 shorter than second metacarpal; phalanges (except ultimate and 

 penultimate) very short or obsolete; shoulder muscles and deep 

 plantar tendons strictly cypseline. 



Bill very small, broadly triangular, depressed, the culmen rather 

 strongly decurved, the maxillary tomium without notch; gape deeply 

 cleft, without rictal bristles; nostrils openmg vertically, near together, 

 longitudinally elliptical or OA^al, nearly parallel, or more or less 

 divergent posteriorly; frontal feathering usualh' extending over 

 lower portion of nasal fosste, sometimes nearly to anterior end of 

 nostril, sometimes also extending forward medially, between base 

 of nostrils; anterior toes subequal (but one or both of the lateral 

 ones usually very slightly shorter than the middle), cleft to the base, 

 and covered with skin or feathers (non-scutellate) ; hallux con- 

 spicuously smaller than lateral toes (sometimes less than half as long 



o- Dendrochelidonid^: Lucas, Auk, vi, 1889, 12. — Maa-optcrygidst' Lucas, Auk, xii, 

 1895, 156. — Macropleryginx Hartert, Das Tier., Podarg., Caprim., Macr., 1897, 63. — 

 Hemiprocnidx Oberholser, Proc. Biol. Soc. Wash., xix, ]\Iay 1, 1906, 68, in text. 



This very well-characterized family of Swifts comprises a single genus {Haniprocne 

 Nitzsch, Obs. Av. Carot. Com., 1829, 15, type, Cypselus lomjipcnnis Temminck; see 

 Oberholser, Proc. Biol. Soc. Wash., xix, 1906, 67, 68), containing about seven species. 

 The nidification of the Dendrochelidonidte is also peculiar, the nest being attached to 

 the upper side of a branch, composed of bits of bark, etc., held together by the bird's 

 saliva, and barely large enough to hold the single egg. They also perch freely upon 

 branches, while none of the Micropodidse do, so far as known. 



& As distinguished from the Tree Swifts, family Dendrochelidonidas. 



