1837.] On some new Genera of Raptores. 367 



Haliaetus. Sub-genus of Pandion P 



Contradistinguished by a long bill, much more compressed on the 

 ridge ; by shorter, rounder wings, never surpassing and seldom equal- 

 ing the tail, and which have the 4th and 5th quills sub-equal and long- 

 est ; by wide, transverse nares of irregular form ; by scaled tarsi and 

 toes, in which moreover the spinous aculcation of Pandion is less de- 

 veloped, and the exterior and hind toes are less mobile ; and, lastly, 

 by talons less compressed and less rounded below — sometimes squar- 

 ed. 



Types. Haliaetus Ichthycetus Horsfieldii, Plumbeus et Albipes, nob. 

 Nos. 10 and 3. 



The bill of Haliaetus is always longer and sharper on the culmen 

 than in Pandion ; but in some species, its cutting edge is as highly 

 festooned as in Pandion ; in others, it is as level as in Aquila : in some 

 again the wings are considerably shorter than the tail ; in others, 

 equal to it. 



Instances of the former peculiarities, Ichthycetus et Plumbeus ; of the 

 latter, Albipes. Halicstus is further distinguished from Pandion by a 

 nude salient brow : but both genera are alike remarkable for the 

 compression of the bill and head, as compared with Aquila, and also 

 for the smallness of the gape. 



The very long unfestooned bill of Albipes is accompanied by a wider 

 gape, by wings equal to the tail, by great size, and by talons perfectly 

 squared below. 



If Ichthycetus, then, be the type of Haliaetus — and no doubt it is — 

 then Albipes is a separate type bearing the same relation to Aquila, as 

 Ichthycetus to Pandion, and connecting Aquila, through Haliaetus, with 

 Pandion. This type I have provisionally named Cuncuma, from its 

 native name. It is a fisher, but not exclusively so ; and is remarkable, 

 like the bird of Washington, for its theftuous propensities*. 



Pandion is the king of fishers, and a more beautiful instance of the 

 adaptation of structure to habits than this genus exhibits, is not to be 

 found in the whole circle of ornithology. The rimiform nares may be 



* I make no allusion to birds which I am not personally familiar with ; but I 

 suspect that the American bird adverted to has a very strict resemblance to our 

 Albipes, a resemblance including habits, size, and structure. If this be the 

 case, it may be ranged by the side of Albipes under the sub-genus Cuncuma, of 

 which the following are the characters. Bill long and void of festoon. Wings 

 equal to the tail. Talons squared below. Size very great. There is a beautiful 

 gradation of characters in these sub-genera, and a correspondent modification of 

 manners, by means of which the type of the fishing eagles is linked with the type 

 of the mammalivorous eagles. 

 3 b 2 



