Dicruridae and their Arrangement. 83 



the gradation of the quills there is some analogy ; but in Irena 

 the 3rd, 4th, and 5th are usually equal and longest, whereas 

 in Dicrurus the 3rd is generally shorter than the 4th and 5th. 

 Beyond these points all resemblance ceases. The tarsus and 

 feet are short and weak in Irena ; the toes and nails are 

 singularly slender for the size of the body ; and the outer toe 

 is free, whereas in Dicrurus it is ankylosed up to the first 

 joint. The tail consists of twelve rectrices, and not of ten ; 

 and this character of itself removes Irena from the Dicruridae, 

 according to Mr. Sharpens own definition"^. The plumage is 

 of a totally difiierent character. The skin in Irena is especially 

 tender; in Dicrurus it is exceedingly tough. In Dicrurus the 

 sexes wear the same plumage, even the ornate plumes ; in 

 Irena the male has a brilliant, and the female a sombre attire. 

 Every species of Irena has a number of fine nuchal hairs, 

 which are wanting in Dici'urus. This last character (unknown 

 to Blyth and Jerdon), together with the short and weak feet, 

 indicates a great affinity to Criniger. The Dicruri are insec- 

 tivorous, some even killing small birds, whereas Irena is 

 frugivorous. The structure of the sternum in Dicrurusis, I 

 believe, diflPerent from that of Irena. The notes of Irena are 

 those of Oriolus, and have no similarity to those of Di- 

 crurus. If we turn to the characters whereby Mr. Sharpe 

 diflFerentiates Irena from the other genera of the Dicruridae, 

 the terms will be found to be not altogether exhaustive or 

 satisfying : — " Tail square ; plumage of upper surface en- 

 amelled." 



Irena criniger. — Mr. Sharpe separates Bornean and Su- 

 matran examples from the Malaccan /. cyanea under this 

 new title, solely on the ground that in /. criniger " the under 

 tail-coverts are produced to the very end of the tail,^' while 

 in /. cyanea they " fall short of the tip of the tail by half an 

 inch." In a Malaccan example {mus. nostr.) the under tail- 

 coverts reach within one eighth of an inch of the tip of the 

 rectrices. But even if the character holds good, how can I. 

 criniger, according to Mr. Sharpe's own views, rank higher 

 than a subspecies? The presence of nuchal hairs is not men- 



* See tlie characters of Dicruridae {t. c. p. 4), 



g2 



