PLATE V 



Pygoscelis papua. 



Fig. I . Embryo, stage 37 (No. 7), deep ventral dissection, ala, allantoic 

 artery; bf, bursa Fabricii; br, bronchus; da, coeliac artery; cr, crop 

 region; crd, thyroid rudiment; da, dorsal aorta; db, ductus Botalli; 

 go, gonad ; gp, genital papilla ; ina, innominate artery ; k, opisthonephros ; 

 lu, lung ; p, pericardiac boundary ; pa, pulmonary artery ; pv, pulmonary 

 vein; rea, renal artery; x, ureter; y. Wolffian duct; s, MuUerian duct; 

 1-5, orifices of air sacs. 



Fig. 2. Skeletal elements, left side, cl, clavicle; cu, cuneiform; 

 fb, fibulare; fi, fibula; ha, hallux; pb, pubis; pt, patella; ra, radius; 

 s, scapula; sm, sesamoid; ti, tibia; u, ulna; mt IV, metatarsal IV; /, //, 

 ///, digits. 



