66 REVISION OF THE GENUS TURDINUS 



One of the consequences of my attempt to obtain a 

 more satisfactory classification is the re-separation of the 

 genus Malacocinda from Turdinus proper, while on the 

 other, hand, I was obliged to remove certain misplaced 

 species and to place them into other more convenient 

 genera. 



In the following arrangement are included the species, 

 collected during my recent sojourn in Central Borneo. 

 A report of the zoological results of the last Dutch scientific 

 expedition to Borneo , of which I had the pleasure to be 

 appointed as zoologist, will be published later on in this 

 periodical. 



The chief principle upon which I have based my ar- 

 rangement is the proportion between the length of tarsus 

 and tail, the first forming a very important moment in 

 the locomotion of these birds, which are passing most of 

 their life-time on the ground, while the last shows much 

 more difference in size than the wing. The wing-formula 

 is the same in the whole group of Timeliine birds and 

 cannot be made use of in the present classification, while 

 the shape of the bill and the position of the nasal aper- 

 ture must be considered as characters of second rank. It 

 is sometimes far from easy to say whether the nasal aper- 

 ture is round and placed in front of the nasal groove, or 

 linear and placed at the bottom of the latter. All this 

 depends much upon the better or less good condition of 

 these parts in the skin, and but too often they are badly 

 mutilated if not entirely destroyed. 



Key to the genera. 



A. Plumage thrusli-like , more or less mottled with 

 black, fulvous or white; feathers on head, hind 

 neck and mantle large and rounded (not fluffy), 

 giving these parts a scaly appearance. 

 a. Size large, thrush-like, tail double the length of 

 the tarsus or longer. 

 a'. Feathers on rump fluffy, unstriped .... Turdinus. 



Notes from the Leyden Museum, Vol. XVII. 



