Genus — SEISUR A. 
Seisura Vigors and Horsfield, Trans. Linn. Soc. 
(Lond.), Vol. XV., pt. i., p. 249, Feb. 17, 1827. 
Type (by monotypy) ... ... T urdus inquietus Latham. 
Also spelt — 
Sisura Strickland, Ann. Mag. Nat. Hist., Vol. VI., p. 422, 1841. 
Vigors and Horsfield wrote : “It is, however, sufficiently distinguished from 
Rhipidura by the tail being even, not rounded, at the end. The bill also is much 
more lengthened, more depressed and stronger ; and it is deficient in those 
elongated bristles which protect the rictus of the preceding birds. The 
formation of the wing also of both these genera will be observed, from the char- 
acters given of each, to be materially different, and the marked scutellation of 
the tarsi separates the present group from the preceding, and indeed from most 
of the Muscicapidce that we have as yet had an opportunity of examining.” 
Gould commented : “ The present genus and Rhipidura are mere modifica- 
tions of each other ; a difference in structure, however, exists of sufficient 
importance to justify their separation, and, as is always the case, a corresponding 
difference is found in the habits and actions of the species.” 
This genus seems to have developed from a “ Rhipiduroid ” ancestor, 
recalling Leucocirca in most respects, but recently it has been separated and 
placed alongside Arses, the glossy head and female breast band suggesting that 
relationship. \ 
Compared with Leucocirca, which Vigors and Horsfield included in 
Rhipidura, the bill is much more lengthened, more compressed laterally not 
depressed ; rictal bristles are present, but not so numerous or prominent. The 
wing formula is practically the same, while the distinct scutellation remarked 
upon can also be seen in specimens in all the “ Rhipiduroid ” series. 
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