156 Notes on the Species of Stenus, Sec. Besides the Stephensian species already noticed in this list, there remains in the ^* Illustrations" — Sp. 22, St. argyrostoma, Staph., which is fuscipes, Erichs. Sp. 55. St. carbonarius (Gyll.), Steph. With this name there are no specimens in Stephens' Collection, but in its place are two insects, viz., fuscipes, Erichs., and /usci-cornis, Erichs. Sp. 59. nanus, Steph. Coll, declaraiiis, Erichs. One of the specimens is St. pusillus of Erichson. XVII. Descriptions of some Species of Brazilian Ants belonging to the Genera Pseudomyrma, Eciton and Myrmica {with Observations on their Economy by Mr. H. W. Bates). By Frederick Smith, Esq. [Read January 1st, 1855,] Genus Pseudomyrma, Guer. Antennce sub-clavate, 13-jointed in the females, 12-jointed in the workers, the antennae slightly thickened towards their apex, not quite so long as the head and thorax, inserted on the anterior part of the face, near the mouth, on each side of a short elevated carina. Mandibles triangular, denticulated on their inner margin. Eyes elongate-ovate, very large, occupying a large portion of the head: ocelli three, placed in a triangle on the vertex. Thorax elongate, compressed at the sides ; the anterior wings having one marginal and two complete submarginal cells, the second receiving the first recurrent nervure near its base; one discoidal cell; legs short and stout. Abdomen ovate ; the first segment forming an elongate pedunculated node, the second large and globose. The name Pseudomyrma is proposed for the insects comprised in this genus by Lund, in the Annales des Sciences Naturelles, 1831; but the only character there given is the extraordinary
XVII. Descriptions of some Species of Brazilian Ants belonging to the Genera Pseudomyrma, Eciton and Myrmica (with Observations on their Economy by Mr. H. W. Bates)