OSTEOLOGY OF BIRDS 



87 



posteriorly, but the spongy parts of the maxillopalatines are not 

 nearly so lofty, and in some skulls of Elanoides these latter only meet 

 upon the basal aspect by the intervention of the tumefied inferior 

 margin of the septum narium, which latter is considerably exposed 

 anteriorly and comes down between them in the middle line. This 

 much, at least, is different from what we find in Circus. On the 

 other hand, Elanoides again agrees with Circus in a very excellent 

 character, for in its cranium we find present the " prickles " that 

 represent the vestigeal basisphenoidal processes. The palatines 

 agree very closely with those of Circus, and its vomer is long and 

 pointed, articulating well back between the palatines, but it is not 

 platelike as in the harrier and in Buteo, and is always riddled with 

 small vacuities of varying sizes ; the palatines, too, exhibit pneu- 



Fig. 39 Mandible of Elanus leucurus 

 seen from above, and somewhat reduced 



Fig 40 Side view (left) of the same bone. Nat- 

 ural size. (Drawn from a photograph; both by 

 the author) 



matic foramina in their postpalatine plates, upon both surfaces, 

 within the mesial border. 



In its inferior mandible, Elanoides agrees almost exactly with 

 Circus, as it does practically in its hyoidean apparatus, but in the 

 kite the ceratohyals are longer than they are in the harrier. 



Concerning the remainder of the trunk skeletons of these two 

 Falcones, Elanoides presents the following principal differences as 

 compared with Circus hudsonius. 



Elanoides has in its shoulder girdle the os furcula of a more con- 

 tracted U-form, the clavicular limbs being nearly in the anteropos- * 

 terior planes, with the hypocleidium aborted, and the upper ends of 

 the clavicles more produced. (They meet the clavicular processes of 

 the scapulae.) The coracoids are short and wonderfully stout. 



