Dicrurus suluensis Hartert, Novit. Zool. (1902), 9, 441; McGregor
and Worcester, Hand-List (1906), 107.
Lapoc, off Siasi (Bartsch); Sulu (Guillemard, Bourns & Worcester).
"The Sulu form differs from the Sula bird in smaller size
(wings and tail) and somewhat smaller glossy spangles on the
breast and from D. borneensis in having a larger bill and longer
tail." (Hartert.) Measurements of this species are given as follows:
"Wing, 145 to 155; tail, 133 to 136; bill, 34 to 36."