ShUFELDT : OSTKOLOGV OF THE FLAMINGOES. 311 



tact with the latter except at their coninieiicements in the acetabular 

 rings. 



\\'ith resj:)ect to the s/x free cainial I'crtel'nc and py<^ost\lc we are to 

 notice that from first to last they gradually decrease in size, and that 

 the lateral processes also become ])rogressively shorter and shorter to 

 be entirely absent in the two last vertebra; and the pygostyle. The 

 neural canal very small at the commencement likewise becomes rapidly 

 reduced in calibre, though it persists as far as the pygostyle, into which 

 it penetrates for a short distance. .\11 the neurapojihyses are very low, 

 thick and stumpy, and exhibit a feeble tendency to bifurcate in front. 

 It is only the last two caudals and the terminal piece that develop 

 hcemal spines, and these are short and pointed, being on the antero- 

 inferior margin of the centrums, and are directed forwards to underlap 

 the vertebra next in front of them. The zygapophyses are aborted, 

 unless it be that the minute bifurcations spoken of above as appearing 

 on the anterior part of the neural spines, represent the rudiments of 

 prezygapophyses, which indeed they may. Each centrum is proc(elian 

 in character, and a hi^mal canal is "absent. In the mounted skeleton 

 of P. antiqiiorum (see Plate IX.), in the collections of the U. S. 

 National Museum, the ultimate " uro-sacral " is not fused with the 

 others, so in this specimen it may be considered as more properly be- 

 longing to the tail vertebrae, thus making seven instead oi six of those 

 bones, as I have stated above for P. rubra. A similar variation is 

 sometimes formed among the A/isercs, where, too, the usual number 

 of caudal vertebrae appears to be six or seven. In the same specimen 

 there is also a striking difference in the ribs from those of P. rubra, 

 for the pelvic pleurapophyses have semi-aborted epipleural processes 

 upon them, and there is a pair of elongated, free "cervical ribs," 

 which lack them altogether. 



Of the Sternum and Shoulder-girdle. — Unlike the sternum of the 

 Ibises of the genus Plegadis, this bone in the Flamingo is, behind, 

 but once deeply notched upon either side of the carina — and in this 

 respect it agrees with the sternum as found in all typical Geese and 

 Swans, and also in many Ducks. The style of the notching, however, 

 is more as we find it among the Geese of the genus Bernicla, only in 

 the latter the lateral xiphoidal processes are longer than the body of 

 the sternum, are more curved, and have their extremities somewhat 

 dilated ; the mid-xiphoidal process is likewise broader in the sternum 

 of the Goose, and its posterolateral angles are produced. In Tantalus 

 the " notching" of the sternum agrees with the Flamingo. 



