EEVIEW OP OIRDS. 443 



Note. — This order emlbruccs the typical forms of tlie group lusessores, and 

 the birds that generally have the highest degree of development. 



In the followiug tables I have tried to use the most important as well as the 

 moBt positive and evident characters, but have in this, like others, met with 

 much difficulty of finding such of the smaller groups, or families and genera, in 

 the higher orders. A great many of the characters used are taken from Sunde- 

 vall ; and in the Passeres several from Cabanis. Their validity has first been 

 fully tested. In consequence of the above-mentioned difficulty we find that 

 the place in the system of a foiin in question cannot always be ascertained from 

 similar tables, as a more minute description is often necessary. It must not, 

 therefore, be expected that these tables should give an infallible gi-ound for the 

 determination of the forms belonging to the respective families and sub-families, 

 but only that they should denote some of the most important characters that 

 form the basis for the groups, and give an easy review of these groups. Such 

 a table shows us most plainly what characters are common and what are not. 



As a great many of the exotic generic forms are not well known to me, I do 

 not insist that they can bo all arranged under the 69 families and 144 sub- 

 families here charcterized, and that the arrangement of other families or sub- 

 families is unnecessary; but I believe that a great part of the genera have been 

 considered. I may mention that the difficulties arising in limiting the fomilies 

 Cornidce, Paridce, and SylvidcB among the Passeres have induced mo to make 

 these families more comprehensive than they have been. 



It seems that the Epimachini and Paradiseini should together form a separate 

 family ; but I have not been able to find any distinguishing characters, common 

 to both, that make them distinct from the Corvidce. The family CorvidcB cor- 

 responds with "cohors Corvi formes,^'' of Sundevall (Sovenska Foghirna ) The 

 Troglodytini include forms of both Troglodytincn and Timalince, Cabanis, ex- 

 ceptmg some with emarginated bill. The other lAotricliidoe,, Cabanis, are given 

 to the Sylvidce, partly to Lanini and partly to Sylvini. It seems that the 

 famWy BrachypodidcB as arranged by Cabanis should at least partly be included 

 in the last-mentioned sub-family (Sylvini,) which, as it also embraces the Syl- 

 triadce, Cabanis, is very rich, and contains about 500 species or more. I even 

 include the VireonincB, Cabanis, in the Sylvicolini, 



