NEW SPECIES OF THE MOTACILLIN^. 191 



6 lateral rectrices, much blanched, increasingly to the extremes which are 

 nearly all white : legs black : bill horn grey : iris brown. Female consi- 

 derably less : 6| inches long : similar to the male, but more dully coloured, 

 and the alar and caudal black plumes of the male, brown in her. 



MoTACiLLA Proper Species, new ; Alboides, nobis. 



The oriental analogue of ^ /6a, cui simill. ; but clearly distinguishable by 

 its white throat, its completely black neck, and the greater blanching of its 

 wings which, when closed, show nothing but white, except on the tertials. 



Colour and size of mature male. Forehead, cheeks, and throat, white, 

 divided by a narrow black line from the gape. Back of the head, 

 with the whole neck, breast,' shoulders, body above, and 8 central 

 tail feathers, jetty: 4 lateral caudals, with the body below and great- 

 est portion of the closed wing, white: quills black internally, and 

 apertly so on the tertials which, however, have very broad margins 

 of white: bill and legs jet: iris brown: 8 inches long by 11|- wide, 

 and less; 1 oz. in weight: tail 3|: tarsus -ff : central toe hind 

 ^ : its claw -j\ : wings 2^ inches short of tail. Amidst all the changes 

 of plumage to which this species is liable, I still think I may safely say 

 that the female (like the young) is slaty above, and white below, with a 

 black gorget on the breast, and a blackish zone round the cheeks : wings, 

 mostly black brown, with a narrow white edging. 



Remai'lc. By comparing the proportions of this species with those of 

 Calcamta, the characteristic difference of structure in 3Iotacilla and 

 Budytes may be at once perceived. 



I am answerable for reducing Enicurus and Budyies to the station of 

 Sub-genera ; but, their internal structure, their habits and manners, are 

 so similar that I cannot imagine the small discrepancy of external structure 

 can want generic division. Certainly, however, there is this difference in 

 the manners of the Enicuri, as compared with the MotaciUa, that tlic 

 former love the sheltered rills; the latter, the open streams; and the 

 respective formation of the Aving in each may be relative to those opposite 

 habits. Through Enicurus and our Daliila, we are led easily from the 



