122 Shufeldt, Material for a Study of the MegapodiidcB. [ 



Emu 

 St Oct. 



merge into the " costal borders " of the sternum, which latter 

 are rather wide from side to side, and support, in either case, the 

 four transverse facets for the articulations of the costal ribs or 

 haemapophyses. Immediately behind these, on either side, rises 

 the immense anterior xiphoidal process, with its broad base, 

 greatly expanded free end, and its straight, sharp, hinder border 

 or margin (Plate XIII., fig. 28). Between this big process and 

 the rather short and narrow xiphoidal one there is a great, deep, 

 elliptical notch, with another smaller one between the posterior 

 xiphoidal process and narrow mid-xiphoidal prolongation, which 

 latter is expanded and notched distally. 



Dorsally, the body of this sternum is considerably concaved, 

 and has nearly a uniform width throughout, though somewhat 

 broader anteriorly than it is behind. In the median line, at a 

 point between the third pair of costal ribs, there is a single, 

 circular, pneumatic foramen ; for not only is this sternum 

 pneumatic, but, to a greater or less extent, all the other bones 

 of the trunk skeleton, with the exception of the os furculum, the 

 caudal vertebrae, possibly the scapulae, and most surely portions 

 of the pelvis. 



Professor William Kitchen Parker, already quoted by me 

 several -times above, says of this part of the skeleton in the Brush- 

 Turkey {Cathetunis) that " the spaces between the forks of the 

 hyposternum and between the hypo- and xiphi-sternums are 

 relatively much smaller, and the external process of the hypo- 

 sternum is twice as broad as in the common cock. As in the 

 Curassow, the sternal keel is deeper than in the type, and is very 

 thick. Altogether, the sternum comes very near that of Crax 

 globicera, the hyosternal processes being thick and short. The 

 episternum is perforated, but it is feebly carinate below, whilst 

 in the Curassow the carination is much developed " {loc. cit., 

 p. 165). 



Professor Parker also gives, in the memoir I have been quoting, 

 some valuable observations on the viscera of Cathetunis lathami ; 

 but this is a part of the anatomy of the Megapodiidcc I have not 

 had the material at hand to go into. 



Skeleton of the Limbs : The Pectoral Limb. — In tlie wing there 

 is but one bone that is pneumatic — namely, the humerus (Plate XL, 

 fig. 21, and Plate XII., fig. 27). Air from the air-sac gains access 

 to its anterior through two or three small foramina in the 

 pneumatic fossa, occupying its usual position on the ulnar side of 

 the bone. This fossa here is small and circumscribed, its bounding 

 outhne being elliptical and sharp-edged. The humeral head is 

 of considerable size and hemiellipsoidal in contour. The vallc}^ 

 between it and the ulnar crest or crista inferior, known as the 

 incisura capitis, is well marked, while the radial crest, or crista 

 superior, is not especially prominent, its base being thick, and 

 extending but a short distance down the shaft. Just beyond this 

 radial crest, on the anconal side of the shaft, we find a deep groove, 

 a little over a centimeter long, for the insertion of the tendon of 

 tlie latissimus dorsi muscle. 



