T. sigmoideum Mayr n. sp. Operaria: Long. 2mm. Rufo testacea abdomine nonnunquam infuscato; pilosa pilis erectis obtusis, antennarum scapo pedi-busque pilis adpressis; opaca abdomine nitido; mandibulae ni-tidae et subtilissiine striolatae; caput dense et subtiliter reti-cuiato-punctatum, fronte et vertice inter laminas frontates ad capitis marginem posticum productas striis longitudinalibus dispersis; antennae 12 articulatae; thorax dense et subtiliter reticulato-punctatus, a latere visus supra subtiliter sigmoideus pronoto et mesonoto supra striis longitudinalibus dispersis et percurrentibus; pronotum et mesonotum connata longitrorsum subtiliter arcuata, hoc postice et lateraliter marginatum; metanotum parte basali elongato-quadrangulari, ad latera distincte marginata, transverse concaviuscula, postice spinis 2 longis, acutis, gra-cilibus, rectis, oblique sursum et retro directis atque modice divergentibus; petioli dense reticulato-punctati nodus anticus subglobosus, nodus posticus transverse ovatus, antico paulo latior; abdomen laeve.

Published as part of Radoszkowsky, O., 1884, Fourmis de Cayenne Française., pp. 30-39 in Trudy Russkago Entomologicheskago Obshchestva 18 on page 33