118 Clark, Tail-feathers and Coverts. L April 



the Flamingo, the Anseres, the Snake-bird, the Giant Petrel, alba- 

 trosses and auks. In most groups of birds, the coverts are of the 

 same number as the rectrices, as shown by the various "picarian" 

 birds, the pigeons, the diurnal birds of prey, the curassows and a 

 few other land birds, and the numerous waders, gulls, terns, petrels, 

 Steganopodes, loons and penguins, among water-birds. There 

 can be little doubt that most species of birds have fewer coverts 

 than rectrices, for here we find the bulk of the land-birds, Passeres, 

 parrots, kingfishers, trogons, motmots, most gallinaceous birds 

 and a few small hawks; oddly enough the Fulicarire alone among 

 water-birds have the number of major coverts reduced. 



For future reference and to aid in the further investigation of 

 this subject, it seems desirable to put my observations on record 

 here. I have arranged them under the orders recognized and listed 

 by Sharpe in 1891 because no more recent classification of birds 

 seems to me as generally satisfactory as his. I have examined none 

 of the Ratitse, Crypturiformes, Opisthocomiformes, Heliornithi- 

 formes, Podicipediformes, Eurylaemi or Menurse. 



Galliformes. A large curassow from Brazil (species unde- 

 termined) had 6 rectrices and 6 coverts. A fine large Tetrao 

 showed 9-9 and a single individual of Lagopus showed 8-8. All the 

 other galliformes examined by me showed fewer coverts than tail 

 feathers. In Numida the formula is 8-6 and in Coturniz 6-4. 

 A single specimen of Cyrtonyx also showed 6-4, but the pygidium 

 was injured, so I am not sure of this genus. The other genera 1 

 examined were Canachites (8-7), Tympanuchus (9-8), Bonasa 

 (9-8), Francolinus (7-6), Phasianus (9-8) Oreortyx (6-5) and 

 Ortyx (6-5). 



Columbiformes. The number of major coverts corresponds 

 to that of the rectrices. Their position is on the outer side of the 

 base of each tail-feather at the middle of the tail but soon they lie 

 above the rectrices. The genera examined were Columba (6-6), 

 Ectopistcs (6-6), Zenaidura (7-7; on one side in one individual, 

 7-8), Melopelia (6-6) and Chaemepelia (6-6). 



Ralliformes. Three species of Rallus and one of Porzana 

 show 6-5, and covert 1 is smaller than 2 and sometimes quite small; 



1 For convenience I use the generic names of the ' British Museum Catalogue." 



