572 SYSTEMATIC SYNOPSIS. — GALLING — PERI STEROP ODES. 
others. A singular circumstance is a lack of the extensive vertebral anchyloses usual in birds, 
all the vertebrae remaining distinct. The palatal structure is curiously like that of Passeres 
(aegithognathous). The crop is said to be wanting in sopie ; as is also the hind toe, and one of 
the carotids. There are some 20 current species of the principal genus, Turnix, to wliich Gray 
adds the African Oriyxelos meiffreni^ and the Australian Pedionomus torquatus. Late studies 
of the group have resulted in the view that it should represeut a distinct order, Hemipodii. 
Elimination of these n on -conformable elements renders the Gallince susceptible of much 
better definition, as follows : — 
Bill generally short, stout, convex, with obtuse vaulted tip, not constricted in the con- 
tinuity, wholly hard and corneous except in the nasal fossa. Tomia of upper mandible over- 
lapping the lower ; culmen high on forehead, the frontal feathers there forming a re-entrance, 
with more or less salience on either side. Nostrils scaled or feathered, in a short abrupt fossa. 
Legs usually feathered to the suffrage, often to the toes, sometimes to the claws. Hallux 
elevated, excepting in Cracidce and Megapodidcs, normally shorter than the anterior toes. 
Tarsus generally broadly scutellate, when not feathered. Front toes commonly webbed at 
base. Claws blunt, little curved. Wings short, strong, vaulted. Rectrices commonly more 
than 12 (not more in Cracidce, beyond). Head and brain small in proportion to the body, as 
in Pigeons. Plumage with after-shafts. Oil-gland tufted. Carotids two (except in Megapodidce). 
No intrinsic syringeal muscles. Sternum generally deeply doubly-notched, and furculuin with 
a hypocleidium. Palate schizognathous. Nasal bones schizorhinal. Sessile basipterygoid 
processes present. Angle of mandible produced into a recurved process. Pectoral muscles, 
three; the second extensive ; femoro-caudal variable ; accessory femoro-caudal, semi-tendinosus, 
accessory semi-tendinosus and ambieus present. Intestinal coeca extensive ; gizzard muscular. 
Nature prsecocial and ptilopaedic, typically polygamous. Chiefly terrestrial. 
The order thus defined is equivalent to the AlectoromorplifB of Huxley (1867), minus 
Pterocletes and Hemipodii. The birds composing it fall into two series or suborders, according 
to the structure of the feet and more essential characters. 
10. Suborder PERISTEROPODES : Pigeon-toed Fowls. 
Framed to accommodate the Old World MegapodidcB, or Mound-birds, and the American 
Cracidce, or Curassows. 
The Mound-birds, Megapodidce, as the name implies, have large feet, with little-curved 
claws, and lengthened insistent hallux. They share this last feature with the Cracidce 
(beyond) ; and the osseous structure of these two families, except as regards pneumaticity, is 
strikingly similar. Both show a modification of the sternum, the inner one of the two notches 
being less instead of more than half as deep as the sternum is long, as in typical Gallince. 
The Megapods do not incubate, and the young pass through the downy stage in the egg, 
hatching with true feathers (p. 226). They are confined to Australia and the East Indies ; 
Megapodius is the principal genus, of a dozen or more species ; there are three others, each of 
a species or two. 
35. Family CRACID^ : Curassows. 
This type is peculiar to America, where it may be considered to represent the Megapodidce, 
though differing so much in habit and general appearance. The aflfinities of the two are indi- 
cated above, and some essential characters noted. According to the latest authority on the 
family, Messrs. Sclater and Salvin, it is divisible into three subfamilies : Cracince, curassows 
and hoccos, with four genera and twelve species • Oreophasince, with a single genus and 
species, Oreophasis derbianus, and the 
