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AET,i9 CONCEENING BIRDS ' TONGUES^ GAEDNER 23 



that feeding habits are similar to the latter, the tongues are wholly 

 unlike and therefore yield more reliable evidence. 



In this family the tongue fulfils all the requirements for taxonomic 

 use in that differences in feeding habits in related forms have not 

 altered the fundamental pattern in the group, so that the tongue 

 alone is sufficient in all instances to refer its owner to the family 

 and in many instances to the correct subfamily and even genus. 

 Conversely, similar feeding habits in unrelated forms (Dendro- 

 colaptinae) have not produced tongues like these, and this is the more 

 striking since the tail, in response to such habits, has taken on the 

 spiny character so common to that of woodpeckers. 



Order PASSERIFORMES 



In this heterogeneous group where so much variability is found 

 in all of the anatomy it is not surprising, to find the tongue taking 

 part in this diversity in form. A brief survey of this has already 

 been given in an earlier part of this paper; it remains to classify 

 and group such differences. 



In many families the thin horny tongue, slightly curled and 

 frayed at the tip, as described for the robin, is found with but slight 

 differences in length and width. Such a tongue has no outstanding- 

 character sufficient to identify the particular family to which it 

 belongs and serves to do no more than to indicate a member of the 

 order. As example Pitta erythrogaster (fig. 90) is illustrative. 



The flycatchers (T3a-annidae) have tongues which are often broad- 

 ened at the middle, somewhat curled, incised at the tip and often 

 slightly frayed. As examples, are Myiochanes inchardsoni (fig. 91), 

 Pyrocephalus ruhinus niexicajius (fig. 92), Sayornis say us (fig. 93), 

 and S. nigricans (fig. 94), NuttaUomis horealis (fig. 95), Emyi- 

 donax griseus (fig. 96), Tyrannus verticalis (fig. 97), and Tol- 

 marchus gabhi (fig. 98). The tongue of Cidicivora stenura is very 

 similar to these forms as is that of Muscisaxicola. niaculirostris. See 

 figure 99 which illustrates Myiarchus dominicensis. 



There is nothing remarkable about the organ in Pachyramflius 

 viridis viridis. 



The South American bell bird, Chasmorhinchus^ has a rather 

 simple flat tongue that is slaty black, matching the gape in color. 

 The postero-lateral branches are long armed with slender spines 

 while the tip is slightly incised and the whole organ is comparatively 

 small in relation to the size of the mouth. 



The Dendrocolaptidae are interesting in that the feeding habits 

 of many of them are similar to woodpeckers without developing 

 tongues like the latter. In most of these the anterior two-thirds 

 or more of the tongue is thin, horny, and translucent, and somewhat 



