Shufeedt on the Os Prominens in Hawksi 197 



heralded, perhaps one or two, possibly six or eight days, pre- 

 viously.* So that a gale would have precisely the effect noticed ; 

 that is, it would strike the loilg migrating line at a certain point 

 where the victims taken would consist largely of the individuals 

 belonging to the same neighborhood, perhaps of but one species 

 or of more, as the case might be. The earlier and later migrants 

 of that neighborhood would alone escape, except the fortunate 

 few that succeeded by favoring circumstances in releasing them- 

 selves from the grasp of the storm. Thus it happens that a 

 species usually abundant in a locality may suddenly become rare 

 and vet the species hold its own over its general range. 



That the ocean is responsible for the lives of many birds has 

 long been known, but the idea that its victims annually reach such 

 figures as to affect the numerical relation of species over extensive 

 areas has not, I think, been hitherto advanced. That such is 

 the fact seems to me certain and it is with the idea of directing 

 the attention of observers to this class of facts, as well as with 

 the hope of eliciting information already gathered but not yet 

 made known, that these pages have been written. 



ON THE OSSICLE OF THE AXTIBRACHIUM AS 

 FOUND IN SOME OF THE NORTH AMERICAN 

 FALCONTD.E. 



BY R. W. SHUFELDT, M.D., CAPT. MED. DEPT. U. S. ARMY. 



It does not seem possible that a bone the size of one which I 

 am now about to describe could have been entirely overlooked by 

 ornithologists, yet after a careful perusal of such parts of the 

 works of the most prominent writers, as refer to the skeletologx 

 of the upper extremity I fail to discover the barest mention as to 

 the existence of any such an one. 



* The departure of birds in the fall is less regular than their return in spring. At 

 least this is true of many species, as for instance the whole Sparrow tribe and many 

 of the Warblers that saunter along as fine weather and an abundant food supply may 

 tempt. The Swallows are the best examples of the other class. Their deliberative 

 gatherings in the fall and prompt departure as though at a preconcerted signal are 

 familiar to all. 



