Zosterops Vigors & Horsf., Trans. Linn. Soc, xv, p. 235 (1827). Type, Zosterops caerulescens Lath. (Australia).
The numerous races into which each species of Zosterops is divided often approach extremely closely subspecies of other species, which renders a clear description of them very difficult. The characters used in the key given below will, however, probably suffice to enable the student to discriminate between them.
Key to Species.
A. Chin and throat bright yellow.
a. Abdomen entirely grey, or with a mere trace of yellow. * Tail long, 33 to 37 mm.:black strongly suffused with green………..Z. palpebrosa, p. 358.
b. Abdomen with yellow central streak. Tail short, 30 to 32 mm. ; practically all black with but little tinge of green………..Z. aureiventris, p. 364.
c. Abdomen yellow all over………..Z. siamensis, p. 364.
B. Chin and throat pale lemon-yellow………..Z. simplex, p. 363.
C. Chin and throat dark greenish-yellow………..Z. ceylonensis, p. 366.