Strumigenys depressiceps

Identification
Bolton (2000) - S. depressiceps was well defined in its original description and succinctly summarised by Brown (1953a). In that publication Brown isolated the species in its own subgenus (Platystruma) because of its extremely flattened head. He later (Brown, 1973a) synonymised this subgenus under Smithistruma and it is now clear that depressiceps is nothing more than a specialised member of the schulzi-group.

The characters described here isolate depressiceps within the group as it is the only known species with a strikingly flattened head, dense stubbly standing pilosity on all dorsal surfaces of head and body, standing dense pilosity on the legs, and an elongate low basal lamella on the mandible.

Distribution based on Regional Taxon Lists
Neotropical Region: Colombia, Costa Rica, Ecuador, Guyana, Honduras, Panama, Peru.

Nomenclature

 *  depressiceps. Strumigenys (Cephaloxys) depressiceps Weber, 1934a: 47, figs. 6, 14 (w.m.) GUYANA. Combination in Smithistruma (Platystruma): Brown, 1953g: 112; in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 118. See also: Bolton, 2000: 218.

Worker
Bolton (2000) - TL 2.5-2.8, HL 0.77-0.80, HW 0.52-0.58, CI 67-73, ML 0.10-0.12, MI 12-16, SL 0.28-0.31, SI 52-56, PW 0.32-0.36, AL 0.75-0.85 (7 measured).

Basal lamella of mandible a long flat-topped rectangle, its length equal to, or even slightly greater than, the distance separating the apices of teeth 1 and 4 (counting from basal tooth). Head strikingly dorsoventrally flattened, its maximum depth 0.50 X HW or less. In profile the depth of the head at eye level is little more than twice the diameter of the eye. Eye relatively large, with 6-8 ommatidia in the longest row and more than 25 ommatidia in total. Anterior clypeal margin convex. Scape markedly dorsoventrally flattened and broad in dorsal view. Pronotum marginate dorsolaterally. Petiole node in dorsal view longer than broad, in profile its dorsal length much greater than the height of its anterior face. No trace of ventral spongiform tissue on the petiole. Head and body densely and quite coarsely reticulate-punctate on all surfaces except the gaster. All dorsal surfaces of head and body densely clothed with short simple stubbly pilosity that is suberect to erect. Hairs shortest on dorsal head and pronotum, longer on mesonotum and slightly longer still on waist segments and first gastral tergite. Dorsal surfaces of femora, tibiae and basitarsi with numerous similar stubbly suberect hairs. With head in full-face view the dorsolateral margins with numerous freely projecting short hairs. Apicoscrobal hair discernible but scarcely longer than the other projecting hairs. Dorsolateral margin of pronotum with a row of laterally projecting curved hairs; humeral hair not strongly differentiated from them, somewhat longer but by no means obviously distinct.

Type Material
Bolton (2000) - Syntype workers and males, GUIANA: Kartabo, 19.vii.1920 (W.M. Wheeler) [examined].