S. ferruginea: capite maximo, longi-tudinahter striato, postice transverso-striato; spinis metathoracis minu-tissimis.
Worker major. Length 3 lines. Dark ferruginous, with the legs pale; rufo-testaceous; the head very large, twice as wide as the abdomen, in front and at the sides roughly striated, posteriorly delicately striated; the sides of the head very slightly rounded, emarginate behind with a central impressed line running forwards and terminating opposite the eyes; the eyes very small and placed at the sides a little beyond the middle; the vertex smooth and shining, with a few scattered fine punctures. Thorax sub-rugose, convex anteriorly and shining, behind constricted and narrowed; the metathorax with two short, erect, acute spines. Abdomen smooth, shining and slightly pubescent. The mandibles have a single tooth at their apex.
Worker minor. Length 1 - 2 lines. This form is of a much paler colour, the larger individuals having the abdomen fuscous, except at the extreme base; in the smaller examples it is only fuscous at the apex; in large individuals the head is slightly striated in front, in small ones it is entirely smooth and shining; the head much smaller in proportion than in the worker major; the mandibles with two or three teeth on their inner margin.
Hab. Celebes (Tondano).
The different-sized workers were taken from the nest by Mr. Wallace.
