BIRDS OF NORTH AND MIDDLE AMERICA. 299 
Medium-sized to extremely small Coraciiform birds with the myo- 
logical formula A, hypotarsus simple, spina externa and spina interna 
present (but short); palate egithognathous (Micropodii) or schi- 
zognathous (Trochili), humerus extremely short and manus relatively 
very long; bill either short and broadly triangular with gape deeply 
cleft and nostrils opening vertically, near together, and nonopercu- 
late (Micropodii) or long and slender with nostrils opening laterally 
and broadly operculate and tongue extensile (Trochili). 
Basipterygoid processes absent (rudimentary in seme Micropodii) ; 
temporal fossee deep; end of mandible truncated; vomer absent or 
rudimentary; nares holorhinal, impervious; coracoids separated; 
metasternum usually entire and convex (truncate or emarginate, 
with two foramina, in Macropterygide), the carina sterna very high; 
only the left carotid artery developed (except in Micropodii, part); 
ceeca absent; oil-gland (if present) nude; syrinx tracheal (Micropodii) 
or tracheo-bronchial (Trochili); intestinal convolutions of type VI; 
flexor tendons of type V or Va, the hallux connected with the flexor 
perforans digitorum ; semitendinosus, accessory semitendinosus, acces- 
sory femoro-caudal, and sterno-coracoideus muscles and biceps slip 
absent, the femoro-caudal muscle present; tensor patagii brevis 
peculiar, no tendon being developed and the fleshy belly running on 
to a special tendon which springs from the lower end of the outer 
surface of the humerus and is continued, parallel to the forearm, 
along the radial margin of the manus. Spinal pteryla well defined 
on neck, forked on upper back; lateral cervical pteryle present, 
lateral cervical apterium absent; lateral cervical, nuchal, and spinal 
apteria present; occipital apterium present (indistinct in Micropodii) ; 
adult downs present (on apteria, only, in Trochili) ; aftershaft present; 
wing-coverts nonoscinine (the inverted middle series wanting) ; sec- 
ondaries 6-11; primaries 10, the tenth, ninth, and eighth (usually 
the tenth) longest; the fifth cubital remex present (except in some 
Micropodii) ; rettrices 10; alula of 0-3 feathers; rictal bristles absent; 
skin of manus dark. Young nidicolous and gymnopedic. 
KEY TO THE SUPERFAMILIES OF MACROCHIRES.® 
a. Palate schizognathous; toes anisodactylous, the deep plantar tendons passerine; 
ribs, 8 pairs; cervical heemapophyses ‘‘U =’’; humero-coracoid groove or fossa 
present; tibial bridge absent; flexor tendons of type Vc; syrinx tracheo-bronchial ; 
bill long and slender, the gape not deeply cleft; nostrils lateral, broadly oper- 
culate; tongue extensile; secondaries 6-7; alular feathers 0-1; frontal apterium 
present; femoral pteryle small, connected with the dorsal pteryla; aftershaft 
small (sometimes rudimentary or, apparently, wanting)...... Trochili (p. 300). 
aa. Palate egithognathous; toes pamprodactylous, the deep plantar tendons cora- 
ciine; ribs, 6-7 pairs; cervical heemapophysis ‘‘ =T’’ ; humero-coracoid groove or 
@ Anatomical characters chiefly from Gadow in Bronn’s Thier-Reich, Birds, Syst. 
Theil, p. 83. 
