200 



NORTHERN ZOOLOGY. 



SYLVIABvE. 



The preceding digressions on the natural arrangement of those two important 

 families, the Laniadcv and the Merulidce, have occupied so much space, that our 

 observations on the remaining- groups of the Insessores must be restricted to 

 results, leaving the facts upon which they repose to be stated on some future occa- 

 sion. In treating of the Si/kiadce, we more particularly regret this necessity for 

 abridgment. No group in the whole circle of Ornithology, as confessed by all 

 writers, is in such a chaotic state of confusion ; yet no group throughout nature 

 that has yet been analyzed, offers a more perfect demonstration of the trinary sys- 

 tem of distribution than his. This subject, as assuming such an important aspect, 

 will be more fully discussed in another work*, now nearly ready for the press. 



The Si/lviadce, or Warblers, may be also termed Ambulating Flycatchers ; 

 since, when viewed collectively, they are only separated from the Muscicapince by 

 a different mode of feeding, indicated by the superior length and structure of their 

 feet : these members, in the Syhiad.ce, are adapted for constant locomotion, either 

 among branches, or upon the ground ; whereas, in the true Flycatchers, the feet 

 are short, small, and feeble, corresponding to the sedentary habits of those birds. 

 Comparing the Warblers, on the other hand, with the Thrushes, we see that the 

 best distinction between the two groups lies in the very character which assimilates 

 the Si/lviadce to the Flycatchers, namely, the basal depression of the bill. We 

 allude, of course, to typical examples ; since all these distinctions are softened 

 down, in proportion as the three groups approximate. 



A careful analysis of this family will show it is composed of three primary 

 circles, each returning into itself. One of these embraces the three aberrant sub- 

 families, the two others constituting the typical and the sub-typical sub-fami- 

 lies, as follows : — 



SYLVIAD^E. 



1. f Bill very slender, suddenly compressed be- 

 Typical group. \ yond the base ; stature very small. 



2. f Bill stronger, gradually compressed beyond 

 the base ; stature more robust. 



Feet more especially adapted for one parti- 

 cular purpose, either for walking, run- 

 ning, or climbing. 



Sub-typical group. 

 Aberrant group. 



SyLVIANjE. 



Philomelinje. 

 Saxicolinje. 



MoTACILLINjE. 

 PARIANiE. 



An Encyclopedia of Zoology, one thick octavo volume, with numerous wood-cuts. 



