326 Proceedings of the Royal Physical Society. 



was read at tlie meeting of the Physical Society in March 

 1890. 



The Accipitrine style of wing coverts closely resembles 

 that of the Gallinse; with this essential difference that, 

 owing to the group under consideration being without the 

 fifth cubital remex, a displacement of all the coverts on the 

 outer, or distal, side of the place of the missing feather results; 

 and a difference in arrangement both marked and easily 

 recognised is made evident. This style is common to several 

 large groups of birds. These are (1) the PSITTACI, the 

 STEIGES, the ACCIPITEES (properly so-called), the 

 HEEODIONES (-the Herons and the Bitterns only), the 

 ANSERES, and the Cormorants. In reference to the last 

 it may be mentioned that the STEGANOPODES, in which 

 the Cormorants are usually placed, embraces birds with 

 very diverse styles of wing coverts, and which are, therefore, 

 perhaps related less closely than has been supposed. The 

 wing of the Wild Duck (Fig. 14), in all but minor details, of 

 no importance in this connection, will serve as an excellent 

 type for every one of the groups just enumerated. It will 

 be observed that there are usually either five or six feathers 

 displaced in such a manner as to project considerably 

 beyond the Median proper. I call this group, for conveni- 

 ence of reference, the Inframedian. In Mr Wray's paper 

 they are ignored as a separate group, and in his figure of the 

 Duck's Wing the artist has, no doubt unintentionally, 

 minimised the extent of displacement. 



VII. The GouRiNE Style. — Reverting briefly to the 

 GALLING, we find in the Peristeropods, such as Crax-, 

 Penelope, and Talegalla, etc., that some of the distal feathers 

 of the Medians show a distinct distal overlap (Fig. 9). 

 There is thus three variations in overlap in the same row of 

 feathers. In other respects the wing style is substantially 

 the same as that of the normal GALLINJ^^. As these birds 

 possess the fifth cubital remex, there is, in consequence, no 

 such dislocation as that described. But, supposing for the 

 moment that the fifth cubital remex were absent, and that the 

 coverts above were accordingly " faulted," as they would be, 

 then the wing of the Peristeropods would agree in all essen- 



