226 ON THE GENUS PYCNONOTUS 



the mantle, with white or ashy white upper tail-coverts 

 and white tips to the tail-feathers, combined with the 

 absolute want of any olive-green in their plumage should 

 form a separate group with the generic name Molpastes 

 Hume. 



The other Asiatic Pycnonoti with gray or brown plu- 

 mage, but wanting the above mentioned peculiarities of 

 Molpastes^ and characterized by always having the outer 

 margins of the quills more or less strongly tinged with 

 olive-green , ought to form a separate genus under the 

 name Laedorusa Reichenb. 



Then follow all the different aberrant forms , which bet- 

 ter would be placed under other, already existing or. new 

 genera, as will be shown in the following key to the 

 genera. 



Key to the genera, 



A. Tarsus longer than culmen. 



a. Feathers on centre of crown much longer than the 

 surrounding ones, forming a distinct crest. 



a'. Feathers of crest sword-shaped, not pointed, and 

 somewhat bent downward. 

 a". Bill pyrrhuline, general color of plumage green. Spizixus^). 

 b" . Bill pycnonotine, plumage not green. . . , Otocompsa. 

 b' . Feathers of the crown pointed, the longer ones 



slightly bent upward, forming a pointed crest . Centrolophus. 



b. Feathers of crown all equally lengthened, or not 

 lengthened at all, never forming a long crest. 



a' . General color eartliy brown or ashy brown , no 

 olive tinge whatever on the plumage. 

 a". Upper tail-coverts white or ashy white, diffe- 

 rent from the back, tail broadly tipped with 



white Molpastes. 



b" . Upper tail-coverts uniform in color with the 



back, tail-feathers never tipped with white . Pycnonotus. 



1) I introduce this genus here , though it is sufficiently distinguished from 

 all the pycnonotine forms by its quite different bill, and though only the ty- 

 pical species is provided with a distinct crest. 



Notes from the Lieyden ]\Xuseum, "Vol. X.VII. 



