Crematogaster difformis

Smith, F., 1857, Catalogue of the hymenopterous insects collected at Sarawak, Borneo; Mount Ophir, Malacca; and at Singapore, by A. R. Wallace., Journal of the Proceedings of the Linnean Society of London, Zoology 2, pp. 42-88 : 76-77

6. Crematogaster difformis .

C. niger; capite thorace multum latiore; thorace dilatata et postice profunde excavato; abdomine cordato.

Worker. Length 2 1/4 lines. Black; head very large, twice as wide as the thorax; the tips of the mandibles, and apical joints of the flagellum, dark ferruginous; the head smooth and shining; the eyes small, placed laterally about the middle of the head. Thorax: the anterior margin rounded, the sides parallel behind; the metathorax greatly dilated at the sides and above, and with a deep excavation behind; the legs stout, with their joints and the tarsi ferruginous. Abdomen heart-shaped, with the base, in some examples, slightly ferruginous.

Worker minor. Differs only in being one-third smaller.

Hab. Singapore; Borneo (Sarawak).

This species resembles the C. inflatus in form; but the swollen portion of the thorax is of a solid consistency; it forms, however, a similar laboratory of saccharine matter; the orifice from which it exudes is not exactly at the posterior angles, but a little way beneath; in some specimens, masses of crystallized particles can be seen beneath the orifice; of this species, both large and small workers have been examined, and the same apparatus is found on them both.