BIRDS—INSESSORES. 127 
a 
and triangular, the posterior extremity bilobed, the anterior usually with the tip horny, 
serrated, or with fibres; more rarely smooth. These furnish important 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 Strisores 
and Vracheophones as tribes of the former. The Sérisores 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. 
