On the genus Icterus ofM. Brisson. 185 



Although M. Brisson united all the birds of this subfamily 

 into one genus, he was aware of the partial differences that ex- 

 isted in their characters, and he distinguished his species accord- 

 ingly by the trivial names of Cassiques^ Troupiales, and Carouses. 

 He even went so far as to designate these assemblages respectively 

 by the more scientifick appellations of Cassicus^ Icterus^ and 

 Xanthornus, But he subjoined no distinguishing characters to 

 the species which he thus denominated ; and it is not easy to 

 determine the limits by which he meant to circumscribe these 

 minour groups. The task of characterizing them has been effected 

 by later ornithologists, but M. Brisson's names, having the advan- 

 tage of priority, have been with justice retained to the modern 

 genera. 



The whole of the subfamily may be observed to have a striking 

 peculiarity in common, namely, the base of the upper mandible 

 passing backwards to some extent on the front of the head. In 

 some birds, however, of the group, the portion of the mandible 

 which thus extends among the plumes of the forehead is broad 

 and rounded : while in others it is narrowed, sharp, and angu- 

 lated. This strongly marked difference induced M. Daudin to 

 separate the former birds into a genus under M. Brisson's old 

 name of Cassicus : * but he still left all the remaining birds undi- 

 vided in one group under the original name of Icterus, His genus 

 which will be seen to be distinguished by other characters besides 

 the breadth and roundness of the base of the upper mandible, 

 may be described as follows. 



Cassicus. Daud. ' 



Rostrum crassum, rectum ; mandibulae superioris basi lata, dc- 

 pressS, rotundata ; naribus ovalibus nudis. 



Alw subrotundatae ; remige 3tia et 4ta aqualibus, longissirais ; 

 lm& et 6t&> 2d& et 5ta fere aequalibus. 



• M. Daiidin has written this word Cacieus^ instead of adopting M. Brisson'* 

 mode of orthography. M. Illiger restores the old name with great propriety. 

 •* Cassicui a maxills basi, cassidis seu galeae instar frontem tegentCy vocatus 

 est: hinc Cacieus fal«o scribitur." Prod. Mam. et Av. p. 214. 



