BLUE-BILLED NUT-CRACKER. _ 55 



Btrengthens this belief. It is also one of the most 

 natural characters of Tenuirostral types that the 

 sexes vary ; witness the whole family of humming- 

 birds, and that of the fruit-eaters (Ampelidce)^ and 

 we may therefore expect to find the same in the 

 Tenuirostral genus of the hard-bills. 



The form of the wings and bill differ from all in 

 this group. The former are very short, and more 

 rounded than in Dertroides. The first quill is not 

 spurious, but formed like the second, which is only 

 half as long again; the third quill resembles the 

 second of Dertroides^ that is to say, it is slightly 

 shorter than the fourth, which is nearly as long as 

 any of the others ; the tertials are not lengthened ; 

 the end of the wings reach only to the base of the 

 tail, which is rounded, having the feathers broad 

 and soft. The feet are much like those of Der- 

 troiaes, but the inner toe is shorter than the outer ; 

 while the nostrils are behind the basal edge of the 

 bill, and hid by the frontal feathers. The bill is 

 lengthened-conic ; the culmen slightly curved, al 

 though the gonys is straight ; the upper mandible is 

 thickest, and the commissure sinuated, as in Der- 

 troides and the ordinary weavers (Ploceus). 



The colouring is simple, that of the bill is very 

 peculiar in some lights; at a distance it appears 

 almost black ; when viewed more closely, however, 

 it becomes of the darkest indigo-blue, but with 

 reflections of a much lighter colour, nearly resem- 

 bling ultramarine, the tips being rich orange. If 

 that which we conjecture be the male sex, the upper 



