082 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



—fOcyptilinse Milne-Edwards, Ois. Foss., ii, 1867-1871. 

 = Micro podoidex Stejneger, Stand. Nat. Hist., iv, 1885, 437, in text. 

 = Mia-opodoidea Lucas, Auk, vi, Jan., 1889, 12. 



= Macroptenjgidx (not of Lucas, 1895) Hartert, Das Tien-eich, Podarg., Caprim., 

 Macropt., 1897, 63. 



Small to rather large swallow-like Macrochires with bill short, flat, 

 and broadly triangular; gape deeply cleft and without rictal bristles; 

 nostrils opening vertically, near together, and non-operculate ; tongue 

 not extensile; palate asgithognathous ; six to seven pairs of ribs and 

 with eight to eleven secondaries and two to three feathers composing 

 the alula. 



Palate aegithognathous ; maxillo-palatines unciform; basipterygoid 

 processes absent; metasternum convex and entire (Micropodidse 

 except Tachornis) or slightly concave with two foramina (Dendro- 

 chelidonidse and Tacliornis); costal process smah, manubrium rudi- 

 mentary, keel very high; coracoid short, not implanted in a groove, 

 the humero-coracoid fossa absent, the epicoracoid feebly developed; 

 furcula widely U-shaped, with hypocUdium small and epiclidium 

 obsolete; ribs, 6-7 on each side, the second to sixth pairs articulating 

 with the margin of the sternum proper and not with the costal 

 process; humerus very short, radius longer, metacarpals very long 

 (except in Dendrochelidonidse) ; cseca absent; only the left carotid 

 artery present (except in Micropodida?, part) ;« semitendinosus muscle 

 absent; anterior toes subequal, cleft to the base, the inner toe more 

 or less reversible,^ the hallux relatively small, directed inward or 

 sometimes forward; deep plantar tendons coraciine (of type Va) ; 

 tarsi never conspicuously longer than middle toe (mth claw), always 

 nonscutellate, sometimes feathered (occasionally the toes also); 

 primaries 10, greatly elongated, either the tenth or ninth longest; 

 secondaries relatively very short, 8-11 in number; alula composed 

 of 2-3 feathers; rectrices 10, always shorter than primaries, the tail 

 very variable in shape but usually more or less forked or emarginate, 

 never graduated or distinctly rounded, the shafts of rectrices (in 

 Subfamily Chseturinie) often very rigid and extruded, or "spine- 

 tipped." 



KEY TO THE FAMILIES OF MICROPODII. 



a. Tarsus longer than first digit; head without crest or ornamental plumes, flanks 

 without a downy or silky patch, and general plumage hard; rostral portion of 

 cranium broad; nasals triradiate, overlapping frontals; ecto-ethmoid wide; 

 vomer T-shaped, much expanded anteriorly; palatines notched exteriorly; 

 metasternum convex, entire (with foramina in Tachornis); ulna shorter than 

 second metacarpal; phalanges (except ultimate and penultimate) very short or 

 obsolete; shoulder muscles and deep plantar tendons strictly cypseline. (Cos- 

 mopolitan, except colder regions.) Micropodidae (p. 683). 



a According to Garrod (Proc. Zool. Soc. Lond., 1873, 471) both carotids are present 

 in Cypseloides fumigatus. 



b Said to be permanently reversed (the toes in pairs) in some genera, but I can not 

 find that this is true- from examination of specimens. 



