PHYLOG-ENY OP THE PAL./EOGNATELE AND NEOGNATHiE. 



Fig. 4. 



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A. — Ventral aspect of the sternum of Dromceus novce-hollandice, to show the form and position of the coraciod 

 grooves and anterior lateral processes. 



B. — Ventral aspect of the sternum of Dromceus (iter. Note the degenerate condition of the coracoid grooves 

 and the well-marked protuberantia stemi. 



C. — Ventral aspect of the sternum of Rhea macrorhyncha for comparison with that of Dromceus. Note the 

 difference in the position of the coracoid grooves, of the articulation for the sternal ribs, the large 

 protuberantia sterni, and the thin places indicated by shading denoting the position of former 

 fenestra? or fissures. 



D. — Ventral aspect of the sternum of an embryo Apteryx after Parker, to show the possible vestigial keel. 



a.s. = articulation for sternal rib. 

 e.g. = coracoid groove. 

 a.l.p. = anterior external process. 



p.s. = protuberantia sterni. 

 p.l.p. = posterior lateral process. 



Tc. = keel. 

 v.c.g. = ventral lip of coracoid groove. 



