LANIAD^S. 125 



one of the most remarkable instances of collateral affinity that the whole circle of 

 ornithology can produce. We must premise, that the apparent essential dis- 

 tinction between the Ant-Thrushes (Myotherince) and the Bush Shrikes (Thamno- 

 phUina) is this : that the former seek their food upon the ground, and are ambu- 

 latino- birds : while the latter confine themselves to bushes, and are arboreal. 

 This difference in economy is consequently marked by a corresponding difference 

 in the structure of the feet. Those of the Myotherince (including Drymophila, Sw., 

 and certain Urotomi, Sw.) have the tarsi much more elongated ; the claws 

 slender, and not fully curved ; and the lateral scales of the tarsi (excepting in one 

 form, which cannot possibly be confounded with Thamnophilus) uniformly entire *. 

 The American Thamnophilince , on the contrary, both in the typical group and 

 in the sub-genus Formickora, have the tarsi shorter, the claws thicker and more 

 curved, and the lateral scales of the tarsi divided into numerous pieces. Near, 

 therefore, as is the approximation between these two groups, we have chosen, for 

 the present, to keep them distinct ; but so far from wishing to bend Nature to our 

 own views, we shall put the reader in possession of our own doubts on the subject. 

 First, it may be said, that even admitting the distinctions of the tarsi, as above 

 stated, to be invariable, still the argument simply amounts to this — that Nature 

 has chosen to mark the real transition from the Thamnophilince to the Myotherinw, 

 in this manner; in proof of which, we have species of Formicivora with remarkably 

 short tails, and with tarsi fully as long as in several Drymophila;. Upon what 

 grounds, therefore, are we to believe that a relation, to all appearance so perfect as 

 that between Thamnophilus and Myothera, is to be called an analogy ; when, had 

 it been consistent with our views to include both in the same family, or to place 

 them at the confines of two families, we should have been fully justified in calling 

 the series a most perfect and unbroken line of affinity? Again ; is it not a violation 

 of Nature to include such small, weakly-constructed birds as Formicivora (some of 

 which are scarcely larger than the Gold-crested Wren) in the same group with 

 birds so large and powerful as the true Thamnophilince ? Thirdly, if this latter 

 objection is overruled by the reply, that size cannot enter into generic characters, 

 upon what principle is the little Pipra albifrons of the old authors separated from 

 these latter birds {Formicivora), when it appears actually to form a passage to 

 Prionops, Vieil., one of the groups of Bush Shrikes ? 



* We here allude only to such species as we have elsewhere described ; since no birds require more investigation 

 than the small Myothera of modern ornithologists : they present some beautiful forms of analogy, representing every 

 family in the circle of the Dentirostres : even the Australian genus, Malurus, has its counterpart among these pigmy 

 Shrikes. An undescribed species now before us, is a perfect representation of LanieUus, Sw. ; while others, by their 

 depressed bill, typify the Todies and the Flycatchers. 



