238 Annals of the Carnegie Museum. 



obturator space. Each pubic bone is a long slender style of nearly 

 uniform width, extending backwards far beyond the rest of the pelvis 

 or even slightly beyond the pygostyle of the tail. These pubic ele- 

 ments are pointed at their distal ends, and are throughout gently 

 curved, much after the manner of an /" 



As the sides of this pelvis behind are nearly at right angles with the 

 roof, we have as a consequence quite a roomy pelvic basin, more or 

 less protected by bony walls. In front, on this ventral aspect, we 

 find the first four leading sacral vertrebrse, having their lateral processes 

 thrown out against the under sides of the ilia. That vertebra which 

 is opposite the acetabulse behaves in the same manner, and in its case 

 the extremities of the apophysial braces are much dilated in order to 

 be more efficient. Between this vertebra and the fore end of the 

 sacrum, the latter takes on the usual enlargement for the accommodation 

 of the sacral enlargement of the spinal cord in that locality. Foraminal 

 perforations for the exit of the nerves of the sacral plexus are double in 

 apparently every case, and, as in other birds, one is placed above the 

 other. 



Skeletons of the tail show a number of points indicative of feeble- 

 ness of development in these Ibises. In the first three the diapophyses 

 are not large, and although they have low neural spines, they are lack- 

 ing entirely in htemal ones. The remaining vertebrae are even still 

 more rudimentary, and although they may have minute evidences of a 

 haemal spine or hypopophysis, they are much aborted in all other 

 directions. Lastly, the pygostyle is much elongated, transversely 

 compressed, small and narrow, and almost as weak as that bone as we 

 find it in certain Grebes. These Ibis-birds have a very light and 

 pneumatic sternum, that is very much concaved upon its dorsal aspect, 

 where the anterior wall is especially developed and nearly vertical to 

 the body of the bone. Its inner side in the middle line is fortified by 

 a thickening, at the base of which occur a few minute pneumatic fora- 

 mina, as there do also a few to the right and left of it. These open- 

 ings are not seen elsewhere on the sternum, except in the pitlets be- 

 ween the small htemapophysial facettes upon the costal borders. 



The sides in front are well-elevated above the thickened anterior 

 border, though the costal processes are much truncated off, and thus 

 made triangular in form. Posteriorly, this sternum is markedly four- 

 notched, and the pair of lateral xiphoidal processes on either side are 

 rather long and slender, — the median one very considerably stouter 



