﻿EXTERNAL ANATOMY. TARSAL SCALES. 1 1 7 



brethren. However this may be, the facts cannot be 

 disputed; and they place in a very strong light the 

 necessity of paying great attention to the scutulation of 

 the tarsi in nearly all ornithological groups, but parti- 

 cularly in the order of Perchers. In further proof of 

 the last position, we may advert to the family of the 

 Ampelidce, or chatterers, the typical groups of which 

 (Ampelis and Casmarhynchus) have the lateral and pos- 

 terior scales oval, and very small, while the anterior are 

 very broad, and embrace one half of the circumference 

 of the tarsus : this structure, with some very slight dif- 

 ferences, extends to all those groups, as Psaris, Pachy- 

 rhynchus, Querula, &c, which are nearly connected to 

 the Ampelidce, although not in the family circle. It 

 would be nearly impossible, and altogether tedious, were 

 we to describe the different patterns which the lateral 

 scales assume on the tarsi of the different genera : those 

 we have already noticed will be sufficient to direct the 

 attention of our readers to the subject. 



(108.) Posterior scales are more rarely seen among 

 the perchers than either of the preceding series ; and in 

 that order they seldom extend, even when they are 

 present, much farther than the upper part of the tarsus 

 adjoining the knee : they do not exist in the robin, 

 their use being superseded by the junction of the lateral 

 scales behind, which thus form a sharp ridge or keel. 

 In the Tyrannula calcarata (fig. 6l.) these scales are 

 perhaps more developed than in any other percher, as 



in this bird they form 

 a short line of acute 

 but very small spines, 

 which would almost 

 tempt us to believe 

 they were employed as 

 a means of defence, 

 something analogous to 

 the spurs of gallinace- 

 ous birds. Through- 

 out the Tanager family we find no instance of posterior 

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