. On the Groups, of the Fakonidce* ' 315. 



included in any of the preceding stirpes, are united among them- 

 selves, as well as separated from all the others, by the bill being 

 lengthened, nearly straight at the base, and hooked only at the 

 apex. Among them are to be found the most powerful birds of 

 the family, and the most destructive in their habits ', their size and 

 strength enabling them to extend their ravages even over the 

 larger animals. They are deficient however in those powers of 

 pursuing their prey upon the wing which belong to the more typi- 

 cal groups ; their flight, although powerful, not possessing that 

 quickness in turning, and that agility in pursuit, which is exhibited 

 in the Hawks and Falcons. They are thus confined in their ra- 

 vages, in common with the other aberrant stirpes, to the prey which 

 they can seize on the ground.* In the lengthened form of the bill 

 they are allied to the family of Vulturidm, which immediately pre- 

 cedes them in the general arrangement of the Raptorial order ; 

 while they differ from them in external character by their heads 

 being entirely covered with feathers. The present stirps consists 

 of a considerable number of species, and is separated also into se- 

 veral generick groups, differing partially in habits and external 

 character ; some being confined to the land in quest of their prey, 

 while others visit the waters for that purpose ; some again being 

 characterized by a length of wing, while others, connecting the 

 group with the short-winged Hawks, are noted for the shortness of 

 that member. The whole however are sufficiently united among 

 themselves by general habits and character, and may be denomi- 



* This striking difference in the habits of the Falconidte was not passed over 

 by the ancients, who were much more diligent observers of Nature than we are 

 in general inclined to admit them to have been. Aristotle expressly refers to it : 

 ysm d£ rail izpxxuV — oixtyepovert S'aXX*)Xo»»' o; /aev yag avrcov tut rris yjjs 

 xa9*i/ui,Emv -evifrova-t r«v •ntpurTtptx.v xai (jwxptta.yovai, WETo/itEvijr S'ou Siyyoc- 

 iovohv* 01 o'ew/ atwpov /u.ev w tivos xXkov jtaSu/itEvw Sypzvovo-iv, tin njr ynt 

 Vovans v) fj.iTEwpou ovx. aTrrovTtzr 01 §£ out' tlti fns yns oi/t' bw' aXKou 

 WD/Atinf Vtyyavov<TiVj aKKa, weto/xeiw •jrupuvrtzi Ka^xmy. De Animal. 

 Lib. ix. c. 24. Pliuy equally distinguishes the family by these differences in 

 habit. Distinctio generum ex aviditate : alii non nisi ex terra rapiunt 

 avem: alii non nisi circa arbores volitantem : alii sedentem in sublimi : alii, 

 yolitantemin aperto. Lib. x. cap. 8. 



