This specimen was molting from a drab to an adult type male plumage. I saw this species only one other time at Quoin Hill, but on December 26 I saw two males feeding among epiphytic plants in the moss forest above Tenom. The condition of the specimen's plumage prevented its identification to subspecies (presumably _A. m. temmincki_). _=Aethopyga siparaja=_ (Raffles): Yellow-backed Sunbird.--_Specimens_, 3: Tawau: [Male] testis 5 x 5 mm., September 2, 1962, MCT 2861. Tiger Estate: [Male], October 11, 1962, MCT 2999. Oil Palm Research Station: [Female], August 13, 1963, ADG 231. This sunbird was common around flowers at Kalabakan and Brantian Estate. Unfortunately, I lack enough specimens to make a subspecific identification. The specimen from Tawau differs from _A. s. siparaja_, however, only in having darker wings; it closely resembles the type and the series that Oberholser used when describing _A. s. ochrapyrrha_. _=Arachnothera longirostris buttikoferi=_ van Oort: Little Spiderhunter.--_Specimens_, 58: Cocoa Research Station: [Male], 16.2 gm., August 13, 1962, MCT 2777; [Male], 15.6 gm., August 22, 1962, MCT 2796; [Male] testis 6 x 4 mm., 16.0 gm., September 13, 1962, MCT 2913; [Female], December 1, 1962, MCT 3399; [Male] testis 4 x 3 mm., December 2, 1962, MCT 3431; [Male], November 27, 1962, MCT 3347; [Female], November 27, 1962, MCT 3348; [Male], November 28, 1962, MCT 3366; [Male], November 28, 1962, MCT 3367; [Female], November 28, 1962, MCT 3368; [Female], November 28, 1962, MCT 3369; [Male], November 28, 1962, MCT 3370; [Female], November 28, 1962, MCT 3371; [Male], November 28, 1962, MCT 3372; [Male], November 29, 1962, MCT 3386; [Male], December 1, 1962, MCT 3397; [Male], December 1, 1962, MCT 3398; [Female], December 2, 1962, MCT 3430; [Female]?, November 30, 1962, MCT 3443; [Female], April 26, 1962, ADG 60; [Male], April 27, 1963, ADG 70; [Male], April 27, 1962, ADG 73; [Male], April 18, 1963, ADG 78; [Male], April 28, 1963, ADG 80; [Male], April 29, 1963, ADG 86; [Male], April 29, 1963, ADG 87; [Male], April 30, 1962, ADG 93. 12 mi. N Kalabakan: [Female], October 16, 1962, MCT 3050; [Male], October 16, 1962, MCT 3051; [Male] testis 4 x 2 mm., October 18, 1962, MCT 3073; [Female], October 17, 1962, MCT 3064; [Male] testis 7 x 5 mm., October 19, 1962, MCT 3079; [Female], October 19, 1962, MCT 3093; [Male], October 21, 1962, MCT 3120; [Male], October 23, 1962, MCT 3134; [Male] testis enlarged, October 25, 1962, MCT 3150; [Male] testis 7 x 5 mm., October 26, 1962, MCT 3156; [Female], October 28, 1962, MCT 3173; [Male], November 2, 1962, MCT 3204; [Male], November 4, 1962, MCT 3209; [Male] testis 5 x 4 mm., November 4, 1962, MCT 3210; [Male] testis 2 x 1 mm., November 6, 1962, MCT 3214; [Female], November 11, 1962, MCT 3252. Kalabakan: [Female], November 15, 1962, MCT 3278; [Female] 2 eggs in oviduct, ovary