1886.] 



CUBITAL COVEKTS OF BIRDS. 



189 



above the greater coverts, and often more, show uniform and uninter- 

 rupted proximal overlap. This arrangement can be very conveniently 

 studied in the Toucans (fi». 6 b), which are nearly always well 

 represented in the Parrot House in the Society's Gardens. The 

 Cuckoos are associated with the Picarian birds in the List ; but as 

 their wing-pattern differs in some essential respects from that of the 

 typical forms, they will be referred to in connection with another 

 series. 



The transition from the Picarian type to the Psittacine is gradual ; 

 indeed some of the smaller Parrots, especially Melopsittacus, might, 

 so far as the wing-pattern is concerned, well stand within the confines 

 of the Picarian group. The chief difference in the case of Melo- 

 psittacus lies in the further increase in the number of rows of back- 

 ward-lapping feathers on the cubital area. Fig. 7 shows this form 

 of wing, which can be easily compared with the living form in the 

 case of so common a cage-bird. In the type of wing-pattern 

 prevailing throughout all, or nearly all, the rest of the Psittaeidae, an 

 additional modification may be observed. The row of feathers 

 coming on next above the Greater Coverts, indicated by the letter 

 C in the following diagrams, is seen to consist of a series numbering 

 generally five or six, which are confined to the distal area of the 

 cubital region, and form a distinct and separate series from the 

 feathers that extend across the median area. They correspond in 

 relative position to the Upper Wing-coverts (tectrices supenores) 

 in the manual region of the wing ; and it might be convenient for 

 the present to refer to those extending over the distal area of the 

 cubital region under the same term, as is done in the specimens 

 illustrative of the structure of birds' wings that Prof. Flower has 

 arranged at the Natural-Historv Museum, The feathers referred 



Fig. 8 a. 



Psiitacus. 



Melopsittacus. 



Ccdopsitta. 



to often form a conspicuous feature on the wing of the living 

 bird, as they are frequently arranged in such a manner that the 

 shafts of three or more of the feathers are in a line. The proximal 

 edges of these feathers are generally as firm as those on the opposite 

 side, and, as a consequence, the whole series slides between the 

 feathers next them on the proximal side in much the same way as the 



