428 REVIEW OF JAPANESE BIRDS. 



no evidence that in any part of the whole palsearctic region breeding 

 localities of the slender-billed race are situated north of those of 

 the thick-billed form on approximately the same degree of longitude, 

 unless Mr. Seebohm be correct in referring the Japanese specimens to 

 the typical form. 



In fact, this identification by Mr. Seebohm seems to be the only foun- 

 dation for his theory of an arctic and a temperate race, as opposed to 

 Blasius's of a western and eastern. Upon the proper reference of the 

 Japanese specimens, therefore, hinges the whole question. 



I have before me four examples from Japan, which I can compare 

 with four from Korea, one from Kamtschatka, and a number of both 

 forais from Europe. According both to Blasius and Seebohm, the slen- 

 der-billed individuals from Western Europe are only immigrants from 

 Siberia ; they will consequently serve as well as specimens from the 

 latter country. 



Both Blasius and Seebohm lay considerable stress on the dimensions 

 of the bills as indicating the subspecific difference. To a certain extent 

 this is so, and an examination of the tables of measurements given below 

 will therefore give some valuable hints as to the identity of the various 

 individuals, but only if the specimens can be examined at -the same 

 time, for it is plain when inspecting a series of these birds that the 

 peculiar shape of the bills in the two birds is of more importance than 

 the length and the height. In the typical form the upper mandible is 

 more swollen, the upper tomium more inflected, and the basal portion 

 of the culmeu straighter and more parallel with the commissure, while 

 in the slender-billed form the upper tominm is hardly inflected at all, 

 and the culmen tapers at once towards the tip from the frontal feather- 

 ing. At the latter point the bills of both forms are nearly of the same 

 height, and consequently Dr. Blasius's method of measuring the bills in 

 the middle is more expressive than that of Mr. Seebohm, who measures 

 them at the angle of the gonys. It is plain that this difference is easier 

 to appreciate in the specimens than to express in words or condense into 

 a satisfactory diagnosis, the more so since the bills in these birds are 

 subject to considerable individual variation in all directions. I will 

 also call attention to the fact that the bills of the resident birds of 

 Europe seem to vary to some extent locally, as both Blasius and von 

 Tschusi-Schmidhoffen have noted a difference in the stoutness of the 

 bill in specimens from Sweden and from the Alps. 



The other character to which Blasius has called special attention is 

 the width of the terminal white band of the tail-feathers. In the typ- 

 ical form the average width is stated to be 18.3 mm , while in the slender- 

 billed subspecies it is given as averaging 27. 1" 1 " 1 on the outer pair. The 

 difference in the width of the white baud is also admitted by Mr. See- 

 bohm, and I find it corroborated by the material before me. i will re- 

 mark, however, that this character is also subject to some individual 

 variation, but, so far as I can make out, there is no local variation 



