Birds of Celebes: Dicruridae. 
439 
crest-plumes in different states of perfection”. Tlie imperfect and irregular deve- 
lopment of these fine naked shafts in at least three East Indian species, when 
adult or even old, seems to suggest that this character is becoming obliterated, 
in other words, that these hairs are ancestral vestiges derived from a form like 
Dicrurus hottentottus of Indo-China. 
In the closely-allied genera, Bhrimga and Dissemurus, one of the most wonder- 
ful developments of racket tail-feathers is seen, the outermost pair of rectrices 
being greatly prolonged, hare-shafted for some distance from the point where 
they Overreach the other tail-feathers, each ending with a long and broad paddle- 
like racket. In Bhringa the shaft passes mesiaUy through the racket, in Dissemurus 
tfie inner web of the racket is very much reduced, but the outer web very broad. 
(See, also, remarks on Prioniturus platurus and Merops ornatus in the Introduction.) 
The white tips on the axillaries and under wing-coverts, which are best 
developed in Sangi birds, are sometimes absent in adults from the mainland, 
while younger Celebes specimens possess them sometimes to as great an extent 
us those of Siao, or even as adults from Great Sangi. But that they tend to 
disappear with age in Celebes shows that the birds of the mainland are more 
advanced in development in this resj^ect. 
The size and extent of the spots on the breast and throat are dependent 
upon the age of the individual. This has ^lerhaps not always been taken suf- 
ficiently into consideration by writers on the next species, D. pectoralis Wall. 
169. DICRURUS PECTORALIS Wall. 
Sula Drongo. 
hicrurus pectoralis (1) Wall., P. Z. S. 1862, 342; (2) Piusch, Neu Guinea 1865, 170 pt. 
(Sula,); (3) Gray, HL. 1869, I, 285, Nr. 4214; (4) Wald., Tr. Z. S. 1872, Vm, 
70; (o) Sclat., P. Z. S. 1877, 101; (6) Salvad., lb. 1878, 88; (7) Tweedd., t. c. 
615; (8) id.. Ibis 1878, 73; ('S'"'*) M. & AVg., Abb. Mus. Dresd. 1896, Nr. 2, p. 15. 
U- Chibia pectoralis (1) Sharpe, Cat. B. Ill, 1877, 240; (2) id., P. Z. S. 1879, 247. 
Dicruropsis pectoralis (1) Salvad., Ann. Mus. Civ. Gen. 1879, XV, 39; (2) id., Orn. Pap. 
TI, 1881, 173 (Obi major); (3) Guillem., P. Z. S. 1885, 571. 
“Sumpolak”, Peling and Banggai, Nat. Coll. 
Adult. Like D. leucops Wall, of Celebes, except as regards the iris, which is red, not white. 
Observation. Other differences, such as smaller size and more brilliant spangles on the hreast, 
as mentioned by Shar))e (a 1), and the presence of long recurved hairs sprouting at 
the forehead, on which Salvadori has laid stress, cannot be admitted as discrimi- 
native characters for this form, since our lai-ge series of Z>. leucops shows that species 
to he highly variable as regards size, extent and tint of the metallic spangles, and 
the presence and length of the fine hair-like recurved shafts at the forehead, the 
differences being in a large measure due to age and to some extent, we believe, to 
sex and season. Dr. Guillemard (h 3) seems first to have pointed out that the 
recurved filaments are absent in many specimens of D. pectm'olis (from where?), with 
wliich he identifies the Sooloo bird, and Mr. AVallace makes no mention of them in 
his diagnosis of the species, though they are present in the type (alj. 
