186 



MR. J, G. GOODCHILD ON THE 



[Apr. 6, 



In dealing with the various modifications, I propose to take the 

 birds as nearly as possible in the order adopted by Dr. Sclater in the 

 Eighth Edition of the ' List of Vertebrated Animals now or lately 

 living in the Gardens of the Zoological Society of London.' 



Fig. 1. 



Illustrations of the terms used in the folloTving description, as shown br the 

 feathers of the Cubital Eegion in the Golden Plover. 



1 to r. Posterior Border. 2 to 2'. Anterior Border. 2' to 1'. Proximal End. 

 2 to 1. Distal Edge of the Cubital Kegion (shown by the thicker line). 

 A. Cubital Reiniges. B. Greater Wing-coverts. C. Supplementary 

 row of Median Coverts, or Upper Wing-coverts. D. Posterior rovr of 

 Median Wing-coverts. E. Second row. F. Third row. The Posterior 

 row of Median Coverts from D, near the Carpal joint, shows Proximal 

 Overlap as far as the point marked with a small cross. Distal Overlap 

 is shown by the mode of imbrication of the Greater Wing-coverts. 



The Passerine style of imbrication represents one extreme of the 

 range of modification observable, and is well exemplified by the wing 

 of Turdus nurula (fig. 2). In this the median coverts consist of a 

 single uninterrupted row of feathers, whose free edges are regularly 

 directed backwards along a curve extending from near the carpal 

 joint towards a point near the elbow. The same figure shows also 

 one of the simplest arrangements of the Lesser Cubital Coverts. 

 Siich an arrangement as obtains in the Blackbird may be traced, with 

 modifications of only minor importance, through some thousands of 



