North- American Kites. 231 



In the skeleton of the leg the fibula is long, or, as we have 

 said above, it may be complete, as in Elnnoides. Aecipitres 

 as a rule, however, usually have the fibula long, so that counts 

 but for little in most cases. We have seen how the hypo- 

 tarsus of the tarso-metatarsus in Elanoides has a subcubical 

 form, in one piece, and once-perforated for tendons, the whole 

 practically agreeing with Pandion; but now in Ictinia the 

 hypotarsus is represented by two small processes, much as we 

 find it in most ordinary Hawks. 



Usually the anterior aspect of the tarso-metatarsus of 

 Hawks, Kites, &c. is longitudinally grooved down the shaft, 

 especially for its proximal half. Now upon the upper third 

 of this surface is seen an elongated tubercle for the insertion 

 of the distal end of the tendon of the tibialis anticus muscle. 



It is interesting to note, and the character is a good one, 

 that in all the Falconinse this tubercle is situated upon the 

 inner side of the aforesaid groove, it being on the outer side 

 in the Buteonince ; while among the Kites it is seen in the 

 middle of the groove, or, if this latter is but faintly marked, 

 at least in the middle of the shaft. 



Remarkable difi'erences are found in the digits of the pes 

 in all of the Kites here examined, for although in all the 

 first three joints of the fourth toe are subequally abbreviated, 

 the distal one of the three may be quite rudimentary, as we 

 find it in Elanus ; again, the prebasal joint of the third toe 

 is more or less shortened, and the basal joint of the second 

 toe is always much abbreviated, while in Ictinia, as we have 

 seen above, it permanently fuses with the joint next beyond 

 it. 



When we come to be thoroughly acquainted with the entire 

 structure, in each case, of the three genera of Kites of which 

 we have presented in brief the osteological characters above, 

 there is no doubt that we shall find them amply supported 

 by the remaining systems in their economies. Indeed, in 

 so far as the systematists have pointed out the external 

 characters of these birds, it would seem to go far towards 

 demonstrating such a matter. 



