32 



ANATOINIY OF VEETEBEATES. 



of the anterior sacral vertehra? ; whilst the posterior ones form a 

 broad middle tract of that part of the pelvic roof: usually perforated 

 by pairs of foramina, as in the Duck, but becoming obliterated 



more or less in Scolopax, Ptili- 

 nopus, Psopliia, Scojys, Ibis, and 

 perhaps in others Avith age. In 

 most Gallinacea, including the 

 Doves, the ilia converge to a 

 less proportion of the anterior 

 sacral spines, and the space at 

 the middle and posterior part 

 of the pelvis formed by the sa- 

 crum, fig. 21, «, c, is both broad 

 and long. In the Tinamus 

 hrasiliensis, figured by Eyton, 

 this part of the roof is almost 

 wholly ossified, as it likewise is 

 in Oreophasis derbianus, where 

 n pair of oblique grooves lead 

 forwards, deepening, to ' ilio- 

 neural ' canals beneath the an- 

 terior sacro- iliac bony roof on 

 each side the neurospinal ridge. 

 In Hemipodius, Columba, and 

 Goura, the pairs of foramina in 

 the sacral part of the pelvic roof 

 are very small ; in Crax Mitu 

 they continue large to a late 

 period. The ilio-neural grooves and canals are seen in most 

 Gallince as in Oreophasis. 



In Cantores, Volitores, Scansores, and Raptores, the proportion 

 of the hind-part of the pelvic roof formed by a neural expanse of 

 the sacrum is less than in Gallince : the ilioneural grooves are 

 commonly wanting. The bony roof is entire in Ncomorpha, 

 Centropus, Psittacus, Falco, Aquila: and the parial foramina are 

 very small in Cypsehis, Trocliilus, Cassicus, Fregilus, and most 

 Cantores : the ileoneural grooves are present in Turacus gifjas, 

 and are open canals in Cypsirhina and some others. In the 

 diurnal Raptores the pelvic roof, of which the sacrum contributes 

 a broad medial tract to about a third of the hinder portion, is 

 strongly and very completely ossified, fig. 23. The ribs of the 

 first two vertebra^ retain their moveable joints : in the third to the 

 sixth vertebra? they abut as parapophyses against the lower border 



Back view of pelvis, Duck. 



