Catalogue of the hymenopterous insects collected at Sarawak, Borneo; Mount Ophir, Malacca; and at Singapore, by A. R. Wallace. Author Smith, F. text Journal of the Proceedings of the Linnean Society of London, Zoology 1857 2 42 88 http://antbase.org/ants/publications/2588/2588.pdf journal article 2588 D09C3FFA-7EB5-4A2D-A55E-A3229619A2A2 3. Trigona thoracica . T. nigra; thorace obscure ferrugineo, alis flavo-hyalinis, abdomine basi pallide testaceo. Worker. Length 3 1/2 lines. Black: the scape of the antennae at the base, the clypeus and mandibles at their base, ferruginous. Thorax: obscurely ferruginous, the legs more or less ferruginous towards their base; the wings flavo-hyaline. Abdomen smooth and shining, pale testaceous at the base. Hab. Singapore.