UIRDS — INSESSORES. 127 



and triangular, the posterior extremity bilobed, the anterior usnaliy witli the tip iiorny, 

 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 Jnsessores into iSlnsores, Clamdtorcs and Oscines, I have followed Cabanis 

 instead of Burmeister, who makes Clautalores and Oscines the sub-orders, and gives Slrisores 

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

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

 are placed among the Clamalores. 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. 



