60 SPECTACLE FLYCATCHER* 



the eye. "We have had an example of this curious 

 structure in the Prionops plumatus figured in our 

 first volume, and it is also observed in the genera 

 Ceblepyris and Perspicilla. What particular object, 

 however, is effected by this singular appendage, is 

 entirely unknown. 



Although we have no personal knowledge of the 

 fact that the two birds, mentioned in the above 

 synonyms, belong to one and the same species, yet 

 there are many and strong grounds for the belief. 

 Their size and proportions are the same ; the simple 

 length of a dried skin, when measured from the 

 tip of the bill to the end of the tail, depends in a 

 great measure in the contraction or distention of the 

 neck in the process of preserving; they both in- 

 habit the same districts, and are always sent to 

 England from Senegal in pairs as male and female. 

 But the chief reason for our forming this belief, is the 

 fact, that in all the other species of Platysteira with 

 which we are acquainted, the sexes differ in the 

 same way ; that is, the male has the throat white, 

 and the female red. Le Vaillant has shown this in 

 two species*, and we have a third similarly coloured ; 

 so that this variation in the colour of the sexes, 

 becomes, in fact, one of the generic characters. 

 Nearly all these species, moreover, have a sort of 

 collar in front of their neck. 



The presumed male has the upper plumage of 

 a deep black glossed with bluish; the wings are 



* Le Molenar, Ois. <TAf. iv. pi. 160 Le Priprit, Ib. iv. 



pi. 161. 



