BIRDS — INSESSORES. 127 



and triangular, the posterior extremity bilobed, the anterior usually with the tip horny, 

 serrated, or with fibres ; more rarely smootli. These furnish imi)ortant characteristics for the 

 division into families and even genera, the variations being quite considerable. 



In dividing the Insessores into Strisores, Clamatores and Oscines, I have followed Cabanis 

 instead of Burmeister, who makes Clamatores and Oscines the sub-orders, and gives Striso7-es 

 and Tracheophones as tribes of the former. The Strisores of Burmeister are not exactly coequal 

 with those of Cabanis, as they embrace the Halcedinidae and Prionitidae, which by Cabanis 

 are placed among the Clamatores. I am not able to say which classification is the more 

 natural ; that of Cabanis, however, answers all my present purposes, besides having been in 

 my mind while preparing the present report, and before becoming acquainted with Burmeister's 

 valuable work. 



