498 SHUFELDT. [Vol. XVII. 



of free sacral ribs already described, and behind them the 

 apophyses of three more vertebrae are thrown out against the 

 under surfaces of the ilia as supporting braces. The eighth 

 sacral also has its processes moderately modified, as compared 

 with the others, for struts to the acetabulae ; and their outer 

 extremities dilate, and are coincident with the lateral salient 

 angles of the sacrum, of which they form a part. 



Pneumatic fossae are seen upon this ventral aspect, near the 

 hinder borders of the ilium, upon either side, and I miss these 

 air holes upon any part of the external surface of the pelvis 

 where they usually occur in birds. 



The middle vertebra of the tail, or, more correctly speaking, 

 the third one of these segments, has the longest transverse 

 processes, and these projections in the other vertebras become 

 gradually shorter as we proceed either forwards or backwards. 

 They are entirely aborted in the last one, which, however, has 

 the longest chevron bone, there being but two of these latter 

 apophyses. The neural spines are quite lofty throughout this 

 series of six caudal vertebrae in Ectopistes, and of its pygo- 

 style I have already spoken above. 



Taken as a whole the body of the sternum is concaved dor- 

 sally, and correspondingly convexed upon its pectoral aspect. 

 The deep carina runs the entire length of this sternal body, 

 being sharp on its concaved anterior border, and exhibiting a 

 broadly rounded carinal angle below. A thickened welt in it 

 passes down from the coracoidal grooves to spread out and 

 be lost before reaching the long margin of the keel. 



The anterior border of the sternum is much thickened, espe- 

 cially in the middle line, within which a single pneumatic fora- 

 men is seen. The costal border, upon either side, or so much 

 as intended for the haemapophysial facets, is concave and 

 limited in length. Either costal process leans backwards 

 somewhat and is quite prominent. 



In front of the costal process, on a line with their bases, 

 the coracoidal grooves are seen to be well marked ; standing 

 between them, in the middle line, the short stumpy spine of a 

 manubrium projects forwards. Although the true body of 

 this sternum is quite narrow for its mesial part, the bone 



