986 MB, W. p. PTCEAFT ON THE [DeC. 13, 



Key to the Spedes. 

 Catamiilvctes. 



a. Width aeross widest part of synsaorum — dorsal view — much greater than 



depth of post-ilium from dorsal to ventral border ... C. cliysolophuK 

 h. Width across widest part of synsacrum equal to depth of post-ilium. 



f C. chrusocome. 



C. pachyrhynchus. 



Pygoscelis. 



a. Innominate free ; median synsacral ridge not expanded in region of ace- 

 tabulum P. adcUm. 



h. Innominate fused with synsacrum ; median synsacral ridge expanded in 

 acetabular region P.papua. 



Aptenodttes. 



a. Size larger ; total length 9"7 in. ; synsacrum not greatly constricted in anti- 

 trochanteric region A.forsferi. 



h. Size smaller, not exceeding 8"5 in. ; sjaisacrura much constricted in antitro- 

 chanterie region A. 2)ata^onicus, 



EXJDYPTUXA. 



a. Size larger, not exceeding 3-4 in E. alhosignata. 



h. Size smaller, not exceeding 3 in E. minor. 



Sphenisctjs. 



a. Pre-ilium truncated anteriorly 8. dewersus. 



b. Pre-ilium rounded anteriorly S. magellanicus. 



E. Pectoral Limb. 



All the bones much flattened dorso-veutrally ; humerus with a large, non- 

 pneumatic fossa at its proximal end, obliquely truncated distally, and grooved 

 for large, ossified sesamoids ; iilnare of great size, and more or less triangular 

 in outline ; Mc. I. fused with Me. II., and without phalanges. 



r. Peltic Limb. 



Width across the tarso-metatarsus nearly as great as the length. Metatarsals 

 more or less perfectly separated one from another by grooves ; no ectotrochlear 

 foramen ; 2nd trochlea shorter than the 3rd, and not directed backwards. 



Key to the Genera. 



A. Anterior face of tarso-metatarsal region (proximal end) flattened, not 

 scooped out so as to be overhung by the fused tarsals ; interosseous 

 metatarsal foramina large and conspicuous ; of the three metatarsals the 

 median is distinctly the shortest ; entocalcaneal crest distinct ; ento- 

 and ectocnemial crests well developed and enclosing a deep gorge ; ecto- 

 enemial crest directed forwards and running down shaft as far as upper 

 third of fibular ridge ; insertion of tibialis auticus marked by a slightly 



hollowed oval scar in upper third Met. Ill Aptenodytes. 



' B. Anterior face of tarso-metatarsal region (proximal end) slightly de- 

 pressed ; interosseous metatarsal foramina small ; intermetatarsal 

 grooves shallow ; of the three metatarsals the III. is the shortest ; cal- 

 caneal crests obsolete ; ectocnemial crest directed outwards, not continued 

 down the shaft ; ento- and ectocnemial crests do not enclose a deep 

 gorge Pygoscelis. 



