278 ME. W. p. PTCEAFT ON THE MOEPHOLOGT AND 



Drom.eus. 



a. Length 17 in. ; pectineal process well developed; dorsal border of pre-ilium 



mncli arched ; obturator fissure nearly closed ; piilio-ischiadic fissure nearly 



closed D. novcE-hollandia. 



b. Length 9i in. ; pectineal process obsolete ; dorsal border of pre-ilium not 



arched ; obturator fissure wide ; pubo-ischiadic fissure very wide . . . . D. ater, 



E. Pectoral Liaib. 



A. Extended forearm and hand longer than the humerus ; ulnars resembling 



that of the typical Neognathte ; radius and ulna long, with but a narrow 



chink between them ; distal end of IMe. IL flabelliform Rhea. 



B. Extended forearm and hand much shorter than the humerus. 



a. Humerus with a shallow, but blind subtrochauteric fossa; a very strongly 



developed liuea aspera for the triceps, forming a conspicuous triangular 

 ridge ; radius and ulna short and bowed ; ulnare a simple nodule ; distal 

 end of Me. II. not markedly expanded ; manus as in Rhea, resembling 

 typical carinate form, though too small for purposes of flight .... Struthio. 



b. Humerus much bowed, without subtrochanteric fossa or indication of 



pectoral crest ; radius and ulna with but a very narrow chink between 

 them ; a vestigial radiale and ulnare ; a vestigial pollex bearing an 

 unequal phalanx, with the Me. III. incomplete and free distally . . . Apteryx. 



C. Extended forearm and hand about equal to the length of the humerus ; a 



subtrochanteric fossa ; radiale and ulnare anchylosed with metacarpals. 



a. Subtrochanteric fossa large ; ulnare indistinguishable ; radiale anchylosed 



with radius and carpo-metacarpus, but distinguishable Casuarius. 



b. Subtrochanteric fossa very small ; no carpal elements distinguishable ; 



neither pollex nor third digit represented Dromaus. 



F. Pelvic Limb. 



When the bones are pneumatic only the femur is conspicuously so ; save in the Dinornithidee 

 the extensor bridge is wanting ; the hallux, when present, is never large. 



a. Toes three in number ; tarso-metatarsus far exceeding femur in length, 

 a'. Ectocuemial crest large, rivalling the procnemial in size ; euto-condyle with 

 a deep lateral pit ; distal extremity of shaft above entocoudyle (lateral 

 surface) with a deep groove, 

 fl". Procnemial crest extending down the shaft ; femur with a large 



pneumatic aperture DromcBUS. 



b". Procnemial crest not extending down the shaft ; femur nou-pneuniatic; 



ungual phalanx of inner toe gi-eatly elongated Casuarius. 



b'. Ectocuemial crest small, a mere tubercle of the procnemial; no ento- 

 condylar pit or groove on the lateral surface of the shaft ; a moderately 

 conspicuous extensor groove ; popliteal fossa of the femur very deep ; 

 lingual phalanges laterally compressed Rhea. 



