BIRDS FROM ISLANDS BETWEEN K1USHU ANO FORMOSA 



and the olive-green of the upper parts, especially on the head, is very 

 frequently (not always) suffused with a distinct rusty brown to a greater 

 or less extent. 



The subspecies is a smaller bird than Z. stejnegeri Seeb. of Hachijö, 

 but is considerably larger than Z. loochooensis with which it can not 

 be confounded and which is found in the more southern islands. It seems 

 that the present form is the only Zosterops occurring in Tanegashima and 

 Yakushima. I regard it as an insular form of Z. japonica which has 

 started on the way of specific differentiation in the two islands mentioned. 



Out of the fifty five specimens, which I call Z. japonica anularis and 

 all which were collected in Tanegashima and Yakushima, twenty-seven 

 may be said to agree perfectly well, so far as concerns the color of plumage, 

 with typical Z. japonica of the main Japanese island, except in the slight 

 fact that the throat is as a general matter of a perceptibly clearer yellow 

 color, which can be detected only by a close comparison of specimens. 

 The remaining twenty-eight specimens, i.e., about half the entire numbei 

 of the specimens before me, show, as already mentioned, some rusty brown 

 coloration in certain parts of the plumage, and at the same time the yellow 

 of the throat is increased in deepness of tone, approaching the cadmium 

 yellow. The rusty brown may be confined to the forehead ; in other cases 

 it extends farther backwards to the top of head and to the cheek ; and 

 in still others it is seen even on the back and rump, where it appears here 

 and there in a few isolated patches amidst the usual olive-green. The 

 rule seems to be that greater the extent of the rusty brown coloration, 

 the brighter and deeper is the yellow of the throat. The extreme cases in 

 which the color variation in the direction indicated is most advanced, can 

 not fail to at once attract the notice of observers, but they merge by a 

 series of transitional grades insensibly into the other extreme in which 

 the color of plumage is scarcely distinguishable from that of typical Z. 

 japonica. 



The measurements are as follows : 



