NOVITATES ZOOLOGICAE XXIV. 1917. 271 



IV. THE FORMS OF PORZANA FUSCA (L.). 



In the Cat. B. Brit. Mtis. xxiii. pp. 146-148, Sharpe united the various 

 forms of this species, only separating phaeopygiis, because he did not know it, 

 or he would undoubtedly not have kept it as another species. 



Sharpe admitted that the species "varies considerably in size," but con- 

 cluded that " it would seem impossible to recognise more than one form." He 

 gave some measurements which clearly showed that specimens from South 

 India and Ceylon and likewise those from the Philippines are smaller than 

 birds from Northern India on the one hand and from China and Japan on the 

 other. 



It is impossible, according to present ideas, to unite all these forms, nor 

 are they, of course, " species," but clearly " subspecies," though their present 

 knowledge is not final, and the distribution of some of the forms not clear and 

 somewhat peculiar. 



Linnaeus described the bird from Brisson, who had it from the Philippines. 

 The PhiUppine form is therefore Porzana fusca fusca (L.). As birds from Java 

 are not separable from the latter, Temminck's Rallus rubiginosus, described 

 from Java, is a synonym. 



'' Zapornia flammiceps" Hodgson, Gray's Zool. Misc. p. 86 (1844), is a 

 nomen nudum, and I consider the name too unsuitable to adopt it for the North 

 Indian form. 



I distinguish the following forms : 



1. Porzana Jusca erythrothorax (Temm. & Schleg.). 



Gallinula erythrothorax Temminck & Schlegel, Siebold's Fauna Japan, Aves, p. 121. pi. 28 (1849 — 

 Japan). 



Forehead to about middle of eyes or greater part of crown rufous ; upper- 

 side dark olive-brown, in fresh plumage with rusty tinge. Underside and fore- 

 head as a rule less deep, paler rufous, than in allied forms. Larger, wings 105- 

 120 mm. {thirty-five measured). 



Japan from Yesso to Kiushiu and Yaku, Eastern China to Yunnan and 

 Siam. 



In Yunnan specimens are sometimes rather darker on the underside, so it is 

 not easy, if at all possible, to distinguish them from large specimens of P. /. bakeri. 

 The largest specimens I have seen are from Japan (wings mostly 110-120 mm., 

 shortest 105mm.); those from China measure 105-1 18mm., once 120 mm. This is 

 probably accidental, and I do not think that the Chinese form is really smaller. 

 The wings of 10 (J from Mengtsze or Mongtsz in Yunnan measure, according to 

 Mr. Outram Bangs, in Utt., 97 to 105 mm., but as he measured the wings "in 

 their natural curve, not flattened against the rule," * we may add 3 or 4 mm., 

 so that they come to about 100-109 mm. 



* I am afraid that Mr. Bangs'sway of measuring the wing is still the usual one, but it is un- 

 doubtedly the wrong way. An absolutely uniform measurement can only be obtained if the wing 

 is flattened against the rule and thus stretched to its fullest extent. By having the same birds 

 measured by brother (and sister) ornithologists in various countries I have proved that we measure 

 absolutely equal, while no uniformity could be attained by measuring " the natural curve." It is 

 also desirable to have a small brass plate fixed at a right angle to the end of the rule, and to press 

 the wing against that plate ; if the finger is used to hold the wing in its position at the end of the 

 rule, small deviations are unavoidable. 



