60 NILS GYLDENSTOLPE, ZOOLOGICAL RESULTS OF THE SWEDISH ZOOLOGICAL EXPEDITIONS TO SIAM. 
In the specimen from Doi Par Sakeng the bill is marked on the label as being horn 
coloured while in the other specimen it is plumbeous. 
This last-mentioned bird therefore seems to be nearer S. rufifrons rufifrons, but 
it has the black shaft-streaks of the feathers of the forehead very distinct, and this stands 
against what is stated by Harrineton who says »that the black shaft-streaks are indis- 
tinct or wanting in rufifrons. The dull rufous colour of the crown is confined to the fore- 
part of the head». 
In my specimen the whole crown and upper nape is cinnamon-rufous (Ridgway, 
Plate 16) and not dull rufous. 
The breast of the Doi Par Sakeng specimen is much brighter coloured than that 
of the other specimen which is dull olive brown shaded with ochraceous. 
I have therefore for the present refrained from giving a subspecific name to the 
specimens collected in Northern Siam, but the Doi Par Sakeng specimen probably be- 
longs to S. r. bhamoensis HARRINGTON which is a more northern and western form, while 
the specimen from Pak Koh belongs to typical S. r. rufifrons Humes. 
When observed these birds kept to the undergrowth among the valleys which were 
mostly clothed with dense evergreen forests. I never saw them sculking about among the 
lower trees or bushes as Mixornis gulartis minor which species they resemble very much 
both as to habits and colouration. A marked difference exists, however, between these 
two species: in Stachyrhidopsis the bill is conical while in M ixornis it is slender and slightly 
curved. 
104. Mixornis gularis. Rarryt. — The Sumatran Yellow-breasted Babbler. 
Mixornis gularis: Miller p. 370; Grant p. 81; Bonhote p. 64; Robinson & Kloss p. 62; Robinson I p. 106. 
od Koh Lak /i1 1914. L=124 mm.; W=56 mm.; T= 55 mm.; C = 13 mm.; Tarsus = 16 mm. 
— Irides: brownish red. Bill: plumbeous. Legs: yellowish brown. 
Only observed a few miles south of Koh Lak in the Siamese Malaya, where a small 
party was met with on the top of an isolated limestone hill near the sea-shore. This spe- 
cies seems to live up in the trees, mixed up together with Herpornis xantholeuca Honas., 
Hypothymis azurea prophata OBERH, and Cyornis sumatrensis SHARPE, and was never 
observed in the undergrowth or in low bushes as its near relative Mixornis gularis minor 
which it resembles very much as to the plumage. It is, however, much larger than that 
species and has the irides brownish red instead of white or yellowish white. 
The Sumatran Yellow-breasted Babbler inhabits Southern Tenasserim, the Malay 
Peninsula and Sumatra. 
105. Mixornis gularis minor. sussp. n. — The Siamese Yellow-breasted Babbler. 
Mixornis rubricapillus: Gyldenstolpe I p. 21; Gyldenstolpe II; Gyldenstolpe III p. 165; Oustalet 1913 p. 91; 
Williamson I p. 42; Williamson II p. 77; Gairdner p. 148. 
