242 
Mr. Blyth's Commentary 
race, similarly assuming the black plumage with full maturity, 
and very rarely exhibiting more than the rudiment of an occi¬ 
pital crest, as distinguished from S. cirrhatus of other parts of 
India and of Ceylon. The latter never attains the black plumage, 
and has always a long occipital crest. Horsfield's type-specimen 
of his Falco limnaetus from Java is identical with the Bengal bird; 
but Professor Schlegel (Mus. P.-B. Astures, pp. 10, 11) de¬ 
scribes a long-crested specimen from Western Java which seems 
to agree with S. cirrhatus of India, while his other Javan 
specimens are clearly S. limnaetus. Even the large and very 
conspicuously distinguished S. nipalensis , Hodgson, is considered 
by Professor Schlegel to be merely a variety of his S. cirrhatus. 
Yet he discriminates Spilornis cheela from S. hacha , which most 
assuredly are less strongly characterized apart than are Spizaetus 
nipalensis and S. cirrhatus. S. nipalensis should occur rarely in 
the mountainous parts of Southern India, as it was obtained by 
the late Dr. Kelaart at an altitude of about 4000 feet in Ceylon. 
Professor Schlegel notes S. kieneri from the Philippines. It 
may be remarked that the black final plumage of S, limnaetus is 
analogous to that of the North-American Archibuteo sancti- 
johannis , if not also to that of Astur melanoleucus , A. Smith (Zool. 
S. Africa, Aves, pi. 18); but see Mr. Gurney's remarks ( f Ibis/ 
1864, p.357). 
39. Spilornis cheela. 
There are several specific races of this type of Circaetine 
birds:— 
(1.) S. cheela (Lath.), Hcematornis undulatus , Vigors, which 
will probably be found to extend, in all suitable localities, 
throughout the Indo-Chinese subregion. To the westward it 
abounds in Lower Bengal and along the Tarai at the foot of 
the Himalaya*. Professor Schlegel notes it from Chinaf. 
* The true Circaeti frequent dry open country, where they prey chiefly 
on snakes and lizards. The species of Spilornis are found more about wet 
places, where they subsist mainly on large frogs (which they clutch in the 
mud) and on the more or less aquatic snakes (as the Tropidonoti and IIo- 
molopsides); hence their feet are almost always more or less clotted with 
sediment, which may render them frequent agents for transporting to a 
distance the germs of aquatic organisms. 
t [Mr. Gurney informs us that S. orientalis, obtained by Mr. Swinhoe 
toy 
