BIRDS OF NORTH AND MIDDLE AMERICA 6 



young ptilopaedic (except in Heliornithes?) and nidifugous (except in 

 Heliornithes ? and Eurypyges) . 



The 9,bove characters are common to a large group of mostly more 

 or less aquatic birds that are related on the one hand to the Charadrii- 

 formes and on the other to the Galliformes, occupying, in fact, a 

 position somewhat intermediate between these two. It is not, how- 

 ever, a homogeneous group, and it is doubtful whether the Cariamae 

 and Heliornithes, at least, should not be excluded. 



The Gruiformes, as here defined, agree with both the Charadrii- 

 formes and Galliformes in possession of the following characters: 



(1) Schizog-nathous palate (desmognathous, however, in Car- 

 iamae and aegithognathous in Turnices) . 



(2) Double head to quadrate bone. 



(3) Union of distal ends of ilium and ischium. 



(4) Absence of slip to accessory femorocaudal muscles. 

 They agree with the Charadriiformes, but differ from the Galli- 

 formes, in the following : 



(1) Basal ends of coracoids separated or merely touch each 

 other. 



(2) Absence of spina interna sterni muscle. 



(3) Intestinal convolutions of Type I (instead of Type V). 

 From the Charadriiformes the Gruiformes differ in 



(1) Heterocoelous (instead of opisthocoelous) dorsal vertebrae. 



(2) Absence of basipterygoid processes. 



KEY TO THE SUBORDERS OF GRUIFORMES 



a. Palate schizognathous. 



6. Accessory tendinosus muscle absent; deep plantar tendons of Types 11 or 

 X; thigh muscle formula A B X; toes laterally lobed; rectrices 18 or 



more Heliornithes (p. 224) 



66. Accessory tendinosus muscle present; deep plantar tendons of Type I; 

 thigh muscle formula ABXY, or XT; toes not lobed (except in Ralli, 

 part) ; rectrices 10-16. 

 0. Hallux present ; metasternum 2 notched or entire ; oil gland present ; adult 

 downs on both pterylae and apteria. 

 d. Metasternum 2 notched, 

 e. Powder downs absent; cervical vertebrae 14-17; nares holorhinal; 

 hallux elevated. 

 f. Oil gland tufted ; tail of 10-14 rectrices ; cervical vertebrae 14-15. 



Balli (p. 38) 

 ft. Oil gland nude ; tail of 16 rectrices ; cervical vertebrae 17. 



Mesoenatides (extralimltal)' 



ee. Powder downs present; cervical vertebrae 18; nares schizorhinal ; 



hallux decumbent; oil gland nude; tail large, fan-shaped, with 



12 rectrices; wing eutaxic Eurypygae (p. 2-32) 



' =Mesitides Sharpe, Kev. Rec. Att. Classif . Birds, 1891, 74 ; Handlist, i, 1899, 

 180. =Mesoenatides Wetmore and Miller, Auk, xliii, 1926, 342. — Wetmore, Proc. 

 XJ. S. Nat. Mus., Ixxvi, art. 24, 1930, 4 ; Smiths. Misc. Coll., Ixxxix, No. 13, 1934, 

 6 ; xcix, No. 7, 1940, 6.— Peters, Check List Birds of World, ii, 1934, 141. 



