238 SYSTEM A TIC SYNOPSIS. — CARINA T^ — PA SSEEES. 



III. Odontolc^. — Birds with teeth, implanted in grooves. Vertebrae saddle-shaped 

 (heterocoelous). Wings rudimentary, wanting metacarpals. Sternum without 

 keel. Tail short. (Typified by the genus Hesperornis, from the Cretaceous of 

 North America. Fig. 15.) 



rV. RAT1T.E. — liirds without teeth. Vertebrae (some) saddle-shaped. Wings rudi- 

 mentary, or at most unfit for flight, with anchylosed metacarpals. Sternum 

 without keel (as in Odontolcce, fig. 15). Tail short. (Embracing the extinct 

 Moas, and the living Ostriches, Cassowaries, Emeus, and Kiwis.) 

 V. Carinat^. — Birds without teeth. Vertebrae (some) saddle-shaped. Wings devel- 

 oped, with rare exceptions fit for flight, with anchylosed metacarpals. Sternum 

 keeled. Tail short (as to its vertebrae, which are pygostyled). (Embracing all 

 living birds excepting the Ratitoe). 



V. AVES CARINATJE: ORDINARY BIRDS. 



The essential characters of this group, which includes aU living birds excepting the 

 ostriches and their allies (^ratite or struthious birds), are the absence of teeth, the saddle-shaped 

 faces of the best-developed vertebrae, and the keeled breast-bone (fig. 56), in combination with 

 the perfection of wing-structure in adaptation to aerial (or aquatic) fhght. The metacarpals and 

 three metatarsals are anchylosed (figs. 27, 34) ; the scapula and coracoid meet at less than a 

 right angle (very rarely more), and the furculum is usually perfect (fig. 59). (In the flightless 

 parrot of New Zealand (^Stringops hahroptilus), the sternal keel is rudimentary.) The caudal 

 vertebrae are few, and the last few (pygostyle, fig. 56) are peculiarly modified to support the 

 tail-feathers in fan-like array. There is normally extensive post-acetabular anchylosis of the 

 pelvic bones, which are normally separate there in the other groups (compare figs. 56 and 15). 



The division of Carinate birds has always exercised the judgment and ingenuity of orni- 

 thologists ; no system that has been proposed has been universally adopted, and few if any of 

 the major groups can be considered established and perfectly defined. The orders of Carinatce, 

 therefore, are still provisional. But a great assemblage of birds have been ascertained to 

 agree (with few exceptions) in possessing certain characters, upon the combination of which 

 may be based an 



I. — Order FASSERES: Insessores, or Ferchers Froper. 



The feet are peii'fectly adapted for grasping by the length and low insertion of the hind toe, 

 great power of apposing which to the front toes, and great mobility of which, are secured by 

 separation of its principal muscle (flexor longus hallucis) from that which bends the other toes 

 collectively (flexor profundus digitorum). The hind toe is always present, perfectly incumbent, 

 and never turned forwards or even sideways ; its claw is as long as, or longer than, the claw 

 of the middle toe. The feet are never zygodactyle, nor syndactyle, nor semipalmate, nor 

 palmate; the front toes are usually immovably joined to each other at base, for a part, or 

 the whole, of the basal joints. No one of the front toes is ever versatile. The joints of the 

 toes are always 2, 3, 4, 5, counting from the first (hinder one) to the fourth (outer front one). 

 The toes are always four in number (excepting Cholornis). (Figs. 36, 37, 42, 43.) Various 

 as are the shapes of the wings, these members agree in having the great row of coverts not more 

 than half as long as the secondaries ; the primaries either nine or ten in number, and the second 

 aries more than six. (Fig. 30.) The tail, extremely variable in shape, has twelve rectrices 

 (\A-ith certain anomalous exceptions). The bill is too variable in form to furnish characters of 

 groups higher than families ; but its covering is always hard and homy, in part or wholly, — 

 never extensively membranous, as in many wading and swimming birds, nor softly tumid, as in 



