-f^ -^ 



1867.] PROF. HUXLEY ON THE CLASSIFICATION OF BIRDS. 471 



slble, for example, to restrict a term so commonly used in a wide 

 signification as Passeres, to the sense in which Sundevall em- 

 ploys it. 



Midler divided the whole of the Insessores, according to the struc- 

 ture of the lower larynx*, into Oscines or Polymyod.e (of which 

 Sundevall's "Passeres" form one family — the Fringillidce), having 

 the lower larynx formed partly by the trachea and partly by the 

 bronchi, and possessing five or six pairs of muscles attached to the 

 ends of certain of the bronchial rings; TracheophoNvE, with the 

 lower larynx formed exclusively by a modification of the lower part 

 of the trachea ; and Picari^, with the larynx either partly tracheal 

 and partly bronchial, or wholly bronchial and with not more than 

 three pairs of muscles. 



Under the head of Picariae, however, Midler included the Cypselo- 

 morphse, Coccygomorphse, and Psittacomorphae, as well as the two 

 J^githognathous families Tyrannidce and Ampelidce ; and thus a 

 group of " Picariae " very different from that of Nitzsch was esta- 

 blished. 



Later authors, adopting Miiller's term of Tracheophonse, have 

 unfortunately extended the group so named to include the Tyrantiidce 

 and AmjpelidtB, dividing the whole of the " Passeres" into CANORiE 

 and Tracheophon.e. 



Burmeister, for example, proposes this arrangement in his excel- 

 lent monograph on Coracina scutata, and speaks of that bird as one 

 of the Tracheophonae ; whereas his accomit of its larynx shows 

 that it is altogether dissimilar to the tracheal lower larynx of the 

 MyiotheridcE, Scytalopodidce, and AnabatidcB, in which alone that t 

 shigular structure has been found. Miiller would have put Coracina 

 among his Picariae. 



If for " Picariae " we substitute a name formed in a manner analo- 

 gous to Polymyodae, viz. Oligomyod.e, the iEgithognathse would -1- 

 be divisible according to their laryngeal structure into three groups ; 

 and it becomes an important question how far the three divisions 

 thus formed are natural, or present other differences beside those of 

 the larynx. 



From this point of view, and regarded as primary subdivisions of 

 the Coracomorphae, it seems to me clear that they are not natural. 

 Burmeister has described Coracina ; I have examined Cephalopterus, 

 Tyrannus, Eurylaimus, Fteroptoclius, and Chasmorhynchus ; and in 

 no one of them does the structure of the skull differ so much from 

 that of a typical polymyodian Coracomorph {e. g. one of the Cor- 

 vidae) as does that of the also polymyodian Coccothraustes. Pipra 

 resembles the Finches. 



The sternum in most of these genera has the same characters as, 

 and presents no greater varieties than are met with in, the Poly- 

 myodae. But among the Tracheophonse the small group of Scytalo- 

 podidce, as Miiller originally stated, have two notches on each side of 



* Though he wavers in his estimate of the taxonomic value of these divisions. 

 See his paper, " Ueber die bisher unbekaunten typischen Verschiedenheiten, «SiC.," 

 Abhand. d. Berl. Akad. 184G, p. 3G7. 



