300 



NOVITATES ZOOLOGICAE XXV. 1918. 



is always some combination of characters present enabling one to differentiate 

 between them. The tails vary so much in length and in so many specimens they 

 are more or less imperfect that tliis member taken on average measurements 

 does not afford much help ; on the other hand the maximum measurements 

 attained by perfect specimens do seem to form a good characteristic. The same 

 remarks apply to the bill. 



As regards size alone the following measurements give some idea of the 

 natural groups into which the geographical races fall, but, as ah-eady stated, 

 in some cases birds of similar dimensions vary greatly in other respects. 



The dififerences which exist in addition to size are dealt with under each 

 individual subspecies. 



(I) Dissemnrus paradiseus paradiseus. 



Cuailus paradiseus Lirni., Sys. Nat. ed. xii. i. p. 172 {ex Brisson). 1766, Siam. 



Dicrurus platurus Vieill., N<mv. Diet. d'Hist. Nat., nouv. ed., ix. p. 588, Malabar and .Siam. 



Ednlius cristdlatus BIyth, J.A.S.B. xi. p. 171. 1842. Tennasserim. 



Type Locality : Siam. 



The typical form of jxiradiseus is a medium-sized bird with a rather small 

 crest the feathers of which curl back only over the forehead and extreme anterior 

 crowi. The tail is well developed, «ith the racquets long and large. The bill is 

 metlium. 



I cannot divide the birds from Central Siam from those of the extreme 

 south of Siam and Tennasserim, but from this point southwards the birds are 

 smaller and the crest almost non-e.xistent. 



The birds in the west of the Malay Peninsula, if we can judge from a large 

 series from Tavoy and Mergui, are larger than those on the east, and may 

 possibly eventually have to be hnked with rangoonensis, but the crests are no 

 larger than in the Siam bird. 



East. 

 West 



(2) Dissemurus paradiseus setifer. 



Ednlius selijer Cah.. Mvs. liein. Th. \. p. III. 1850. 



Type Locality : Java and Sumatra. 



This form is shghtly smaller than paradiseus, with a comparatively still 

 shorter tail, but differs principally in having practically no crest. 



