340 OSTEOLOGY OF PARID^, SITTA, AND CHAMPA LUCAS. 



The sternum flares considerably i^osteriorly and the costal processes 

 are high, acuminate, and directed well forward, their shape being prac- 

 tically the same throughout the group. 



The varying pneumaticity of the sternum will be treated of farther 

 on, but it may be noted that when this bone is pneumatic there is a 

 single opening in the dorsal aspect of the sternum just above the an- 

 terior origin of the keel. 



The coracoids possess a moderate flange, or ridge, running from the 

 epicoracoid about half way up the shaft, but it is by no means so well 

 developed as in the Thrushes, where this character appears to be carried 

 to its extreme. 



The hypocleidium is long, slender, and bent upward much as iu the 

 Wrens. 



The scapula is stout and regularly curved downward for its distal 

 half, the various species examined being unusually uniform in respect to 

 the shape of this very variable bone. 



The dorsal aspect of the pelvis, which is constant iu shape through- 

 out the grouj), so far as examined, can be better understood from the 

 accompanying figure than from any detailed description. 



a b e 



4 



Fig. 3. — o, pelvis of Campylorhynchui: affinis; b, pelvis of Pn rus hicolor ; c, pelvis of Merulu migratoria. 



In general i)attern it very closely resembles that of the Thrushes, 

 the posterior portion in particular being characterized by the breadth 

 and squareness so marked in that group of birds. 



The ilio-neural grooves are open, and the obturator foramen is sepa- 

 rated by a considerable bar of bone from the obturator space. 



The " sacrum " is wide, more or less keeled and deeply pitted, the pits 

 seemingly marking the intercentral spaces. 



If I am correct iu my count the following species have the "sacrum" 

 composed of five presacrals, two sacrals, and five caudals : Parus 

 ater, P. carolinensis, P. montanus, P. hudsonicus, P. coeruleus^ P. bicolor, 

 Auriparus Jlavkeps, ^ISgithalus caudatus. 



The only specimen of Parus major at hand appears to have but four 

 presacrals, two sacrals, and four caudals, but there is an abnormal look 

 about this sacrum, and there seems to be a little uncertainty (if the 



