Shi'kkldt : OsTEOLOcv OF riir, Hf.rodiones 



187 



the Great Blue Heron, is a large bone. Its sternal extremity is much 

 spread out and cjuite thin and plate-like. Articular surfaces occur on 

 both aspects of this end of the bone, for the fellow of the opposite 

 side and the sternum. One would think, and naturally, that these ex- 

 tremities of the coracoid would be quite unlike, from the fact that they 

 cross each other in articulation, and are fitted in differently directed 

 grooves on the sternum. Such, however, is not the case, for with the 



Fig. 13. Dorsal view of the pelvis of Ardea herodias. Natural size, and drawn 

 by the author, as in the case of all the other figures, from the skeleton of the same 

 specimen. 



sole d fference of a slight asymmetry of the articular facets, these 

 bones are no more unlike than we find them in the majority of birds. 



The shaft of a coracoid is slender and somewhat laterally com- 

 pressed, a compression that is extended to the head of the bone, where 

 it becomes decidedly marked. The summit of the bone being capped 

 with a tuberous crown which curls over mesiad, and extends backwards 

 to merge into the glenoid cavity. This latter is ample and fully two- 

 thirds of the surface is afforded by the coracoid. The scapula process 

 with the line of its articular surface at right angles to the long axes of 

 both bones, is no larger than is just necessary to accommodate the head 

 of the scapula. 



It never meets the furcula in any of the Herons that I have seen, 

 and in all of these birds the bones of the pectoral arch are completely 

 non-]jneumatic. 



The coracoid of A. candidissima differs in no particular from the 

 bone I have just described for Ardea herodias : while though Nycti- 



