4. Labiobaetis difficilis (Mueller-Liebenau, 1984) Figures 8, 53b

Diagnosis.

Larva. Following combination of characters: A) dorsal surface of labrum with submarginal arc of 1 + 7-8 feathered setae; B) labial palp segment II with thumb-like distomedial protuberance, segment III oblong, apically slightly truncate; C) maxillary palp approx. as long as galea-lacinia; D) fore femur rather broad, length 3.4 × maximum width, dorsal margin with a row of ca. ten curved, spine-like setae; E) fore claw with 11-12 denticles; F) paraproct distally not expanded, with 30-35 stout marginal spines.

Examined material.

Paratype. 1 larva (on slide, no. 36), W. Malaysia, Gombak River, 4 ½ miles N of Kuala Lumpur, 6.II.[19]69, Bishop leg.