146 Mr. Swainson on two new Genera of Birds, 



The Formicivorce or Ant-Wrens, are all of them very small ; 

 and in an artificial arrangement might very well be associated 

 with the Warblers. In all but their slender bill, they present a 

 perfect miniature resemblance to the true Thamnophili^ even to 

 the lateral scales of their tarsi, which are small and numerous. 

 They diifer from the Dri/mophi!ce by their comparatively short 

 legs, which are obviously not intended for walking. We know 

 little of their natural economy, further than that they frequent 

 bushes and the low branches of treeSjwhich theyprobably cleanse of 

 those small insects, passed over by their more powerful brethren. 



I should have had some hesitation in placing this group of little 

 birds, so near to that which comprises the powerful Thamnophilif 

 but for the figure and description of the Fourmilier tachet, given 

 in the Planches Coloriees, PI. 179, f. 1.2. It will be perceived 

 that in the series of Thamnophili described in the last number of 

 this Journal, the species are characterized by a shorter and more 

 rounded tail, and that they gradually diminish in size until we 

 reach T.ferrugineus, which is less than a Sparrow. The Four' 

 miller iachet is even smaller ; yet, in its strong and compressed 

 bill, and short rounded tail, it exhibits the two most prominent 

 characters of the lesser Thamnophili. To that group it may, there- 

 fore, safely be referred. 



On the same plate is figured another bird, (also referred to the 

 genus Mi/othera,) by the name of Fourmilier gorgeret. It is of 

 the same size as the last, but with a bill much more slender, and, 

 to all appearance, perfectly agreeing with that of Formicivora, 

 Here then we may fairly presume that the passage from one 

 group to the other takes place. 



We cannot be sufficiently thankful to M. Temminck, (however 

 the above inference may militate against his own particular views) 

 for having furnished ns with the means of tracing one of those 

 beautiful gradations, by which natural groups are insensibly 

 united. 



The short tailed Thamnophili may perhaps hereafter be found 

 sufficiently numerous to constitute a separate genus ;^ but in our 

 present stale of knowledge, they may be considered as forming 

 only a sectional division. 



