The genus Molpastes comprises some Bulbuls which are amongst the most familiar of Indian and Burmese garden birds. They are very widely distributed and though there are but few species these are represented by very numerous geographical races.
In Molpastes the crest is thick and of considerable length, the feathers growing from every portion of the crown and nape. The nuchal hairs are extremely short and difficult to detect. The wing is blunt and the tail very slightly rounded. All the birds of this genus are remarkable for the bright colour of the under tail-coverts and are further to be recognized by the broad white tips to the tail-feathers.
One of the species or races hitherto recognized cannot be maintained. This is Molpastes magrathi (Whitehead, Bull. B. O. C, xxi, p. 48) which is only a rather common hybrid between M. h. intermedius and M. leucotis, partaking of the characters of these two birds in varying degree, some individuals showing more of the former and some more of the latter.
The question of the status of the Chinese birds chrysorrhoides is one of some doubt. Robinson and Kloss consider that there are two good species, chrysorrhoides and haemorrhous, both containing one or more races. To me it seems that we have but one species, extending from Ceylon to China, for there is no real break in the continuity of gradation from the dark western forms with black ear-coverts to the pale eastern forms with almost white ear-coverts. At the same time, all along the joining line of Molpastes h. burmanicus, M. h. nigropileus and M. h. bengalensis -on the West with M. h. chrysorrhoides on the East we have not only many intermediate birds, which might equally well be assigned to either form, but there are many birds, the majority in fact, which can quite definitely be credited to one or the other. Thus there are in the British Museum Collection specimens from the Shan States, Yunnan, Siam, Karenni, Tenasserim, etc, some of which are labelled chrysorrhoides, some nigropileus, some atricapillus and some klossi but of the birds so labelled there are many of which it is impossible to say to which race they belong. Davison, Armstrong and others obtained birds at the same place about the same dat,e which they had no difficulty in calling chrysorrhoides or nigripileus, yet others again are referable to either. It appears to me that all along the Siam-Burmese boundaries there is a narrow region in which there is no stable form found and where, evidently, there are such conflicting conditions in the environment that Nature has not yet had time to evolve one definite form. It is, of course, true that in all lines of demarcation between geographical races intermediate forms are the rule but in this intervening territory intermediate individuals are less common than such as can be definitely assigned to one or the other of the races in the adjoining area.
In view of the many individuals which are exactly half-way between chrysorrhoides and their next-door neighbours, I propose in this work to treat all the forms as geographical races of haemorrhous.
Molpastes chrysorrhoides klossi Robinson, Bull. B. O. C, xli, p. 12 (1921) does not seem to be maintainable; the Museum series varies in wing measurements between 87 and 104 mm., whilst the very large series of Chinese birds range from 90 to 107 mm., one huge bird from Amoy having a wing of 111 mm. On the other hand, it is quite possible that the birds of West "Siam may be separable as somewhat smaller and darker on an average. The series in the British Museum from that country is insufficient to determine this point.
Key to Species and Subspecies.
A. Under tail-coverts red.
a. The black of crown sharply defined and not extending to the hind-neck.
a1. Ear-coverts black and not distinguishable from the crown.
a2. Back dark brown, feathers……………….. [p. 383. narrowly edged with white. M. haemorrhous haemorrhous,
b2. Back paler brown, feathers broadly edged with white . M. h. pallidus, p. 385.
b1. Ear-coverts brown, contrasting with black of crown.
c1. Chin, throat and upper
breast deep black M. h. burmanicus^ p. 385.
d2. Chin and upper throat only
black M. h. nigripileus, p. 386.
c1 Ear-coverts whitish like the lower plumage ; point of chin
only black M. h. chrysorrhoides, p. 387.
b. Black of crown extending into hind-
neck and back and not sharply defined from brown of latter, d1. Black extending far on to back
and breast M. A. bengalensis, p. 387.
e1. Black extending only onto hind-neck and shading into brown on
breast M. h. intermedius, p. 389.
A. Under tail-coverts yellow.
c. Forehead and long crest hair-
brown, each feather edged with [p. 389.
greyish white M. leucogenys leucogenys,
d. Forehead and crown black; no
crest M. I. leucotis, p. 390.
e. Forehead and crown with short
full crest black M.l. humii, p. 391,
* Alcurus striatus paulus Bangs & Phillips, Bull. Mus. Comp. Zool., lviii, p. 284.