﻿EXTERNAL ANATOMY. CONCAVE TAIL. 105 



stitute the Rasorial division of the Laniadce, this singular 

 form of tail nearly pervades the whole group. We 

 see it again in the rare Leiothrioc furcatus, Sw. 

 {fig. 53,), which is the Rasorial genus of the chat- 

 terers (Ampelidce). But we must look for its most 



striking and magni- 

 ficent development in 

 the Menura, where it 

 is also combined with 

 feathers of the fan- 

 shaped structure. We 

 may here remark that 

 there is one solitary in- 

 stance where these long 

 exterior feathers are turned inwards instead of out- 

 wards : this occurs in a humming-bird, figured by Ed- 

 wards, as a native of J amaica ; but we have never yet 

 seen it, nor is a specimen known to exist at this time in 

 any museum. 



(98.) 11. Boat-shaped, or concave tails, are still more 



extraordinary, and ap- 

 pear restricted to two 

 natural groups among 

 the SturnidcB, or star- 

 lings, namely, the 

 grackles of America (Quiscalus), and the Lamprotor- 

 nince, or shining thrushes, of Africa. In the former 

 we know at present but of one species ; but the whole 

 of the latter appear to have tails, the sides of which, 

 when expanded, are bent up like the sides of a 

 boat, so as to leave the central part hollow and very 

 concave : this appearance, however, is generally lost in 

 the preserved specimens, so that these birds then appear 

 to have only an ordinary rounded tail. Of the pro- 

 bable use of this singular structure we can form no 

 correct idea. 



(99*) 12. Compressed, or erect tails, are nearly and 

 obviously related to those which are boat-shaped, inas- 

 much as both assume forms altogether different from 



