542 



CnORDATA 



it is probable that (lie Ralites have descended from carinatc forms by loss of 

 power of tli,i;hl. The anatomical distinctions between the various families load 

 one to belie\e that the\- ha\"e arisen from dilTerent groups of carinates and hence 

 do not form a natural assemblage. 



Section I. STI^UTHIOXES, long humerus, legs and neck. Stritthion- 

 ID.E, two-toed ostriches of .\frica, Slnilliio. Rheid.ic, South .\merican three- 

 toed ostriches, Rhea. Section II. C.\SU.\RIN.\; three toes, humerus short. 

 Droiiu,:'ns. emus; Casiiariiis, cassowaries. Section III. .M'Tl'^RVGI'^S, bill 

 long, nostrils near tip, rudimentarv wing skeleton; four toes. A/y/cryx, New 

 Zealand. The Dimoi^xithid.t:, three toes, wing skeleton absent; giant birds 

 of New Zealand; now extinct, apparently contemporaneous with man. .F.pior- 

 itis, a gigantic bird of ^ladagascar, possibly allied. Skeletons and eggs holding 

 two gallons found in alluvium. 



Order IV. Carinatae. 



The name refers to the presence of the keel to the sternum, correlated with 

 the powers of flight possessed bv most species. Other characters are the pres- 

 ence of rectrices and remiges on tail and wings, and the fusion of clavicles to a 

 furcula. Some strong fliers, like the raptores and albatrosses, have but a small 



Fig. 5Q4. — Foot forms (from Schmarila). a, semi-palmate, wading of Ciconia: 

 b, perching of Tmdus: c, rasorial of PJuisiaiius: J. raptorial of Faico: c, adherent of 

 Cypseliis: /, cursorial of SInilhio: x. 7.\■'^o>h\c^v\ (scansorial) of Pirns: h. lohate of 

 Podiccps: i, lofiale ami scalloped of J'lilicu: k. palmate of Anus: I, totipalinale of 

 Pliaclhon. 



carina; in many poor fliers the carina may be entirely absent. The furcula is 

 not always present, tlie clavicles not uniting (many parrots and toucans) or 

 being absent (.\rcsi(cs). The remiges are also degenerate in some, as in the 

 penguins (which arc llightless, although they have a strong carina), where they 



