Sclater on the Systema Avium. S3 



ployed in the ' Nomenclator ' as still the most convenient to be 

 adopted, and to place the Acromyodi abnormales of Garrod 

 (which, being extra-American, were not included in the -No- 

 menclator') at the end of the Passerine series under the name 

 Pseudoscines. The arrangement would then come out as fol- 

 lows : — 



i. Oscines. 

 ii. Oligomyodce. 

 iii. Tracheophonre. 



I a. Atrichiida-. 

 iv. Pseudoscines > ., 



ft. Menundae. 



We thus get the advantage of having what are certainly the 

 most anomalous forms of Passerine birds yet known at the end 

 of the series. 



We must now approach the still more vexed question of the 

 division of the Oscines into families. The difficulty here ob- 

 viously arises from the fact that the Oscines are all very closely 

 related to one another, and, in reality, form little more than one 

 group, equivalent to other so-called families of birds. As, how- 

 ever, there are some 4700 species of Oscines known, it is abso- 

 lutely necessary to subdivide them ; and the task of doing this in 

 the most convenient and natural way is not an easy one. 



Sundevall. who has certainly devoted more time and attention 

 to the external characters of the Passeres than any other natural- 

 ist of this century, in his last work (• Methodi Naturalis Avium 

 disponendarum Tentamen,' Stockholm, 1S72) divided his "Os- 

 cines laminiplantares " (which are equivalent to the Passeres here 

 considered, with the exception of the Larks) into six "Cohortes." 

 as follows : — 



i. Cichlomorplw .... 50 fam. iv. Certhiomorph;* .... 3 fam. 



ii. Conirostres 15 " v. Cinnyrimorpha? .... 5 



iii. Coliomorphas .... 15 " vi. Chelidomorphae . . . . 1 



SundevalPs characters are derived partly from the structure of 

 the bill and partly from other points, and his six primary 

 divisions seem to me to be very naturally conceived. On the 

 other hand, Mr. Wallace's well-known arrangement of the Pas- 

 seres, first proposed in this Journal.* and subsequently followed 

 in his great work on distribution, is based entirely upon the 



* Ibis, 1874, p. 406. 



