Cryptopone Emery, 1893 Taxonomy. The genus Cryptopone is assigned to the tribe Ponerini (Bolton 2003). Morphology. Workers of Vietnamese species have the following features (see also Schmidt & Shattuck 2014): Worker monomorphic; head in full-face view subrectangular or subtrapezoidal; frontal lobes horizontal, separated from each other by a longitudinal sulcus; antennal scrobe absent; anteromedian margin of clypeus weakly convex; mandible subtriangular, with a distinct apical tooth followed by 3–8 teeth on masticatory margin; basal portion of mandible with a distinct circular fovea or elongate depression dorsolaterally; antenna 12- segmented, gradually incrassate from segment III to XII, or with a 4-segmented club; eye absent, or present but reduced, consisting of a few ommatidia; eye, if present, located on the side of head close to mandibular insertion; mesosoma in lateral view with straight or weakly arched dorsal outline, or dorsum of propodeum lower than pronotum and mesonotum; mesosomal dorsum in dorsal view constricted behind mesonotum; mesonotum well margined anteriorly by promesonotal suture and posteriorly by metanotal groove; mesopleuron defined weakly from mesonotum by a faint suture or not defined from mesonotum, and defined well from metapleuron by a suture and/or groove; propodeum unarmed; orifice of propodeal spiracle oval or elliptical; propodeal lobe much reduced; outer surface of tibia and basitarsus of mid leg with thickened peg-like setae mixed with finer normal pilosity; apicoventral part of foretibia always with a simple spur behind a large pectinate spur; apicoventral part of mid and hind tibiae often with an additional smaller, simple or barbulate spur in front of a large pectinate spur; petiole without anterior peduncle; petiolar node in lateral view high, with an inverted V- or U-shaped outline; subpetiolar process present as a thin lamella, variable in size, anteriorly without a conspicuous round depression, posteroventrally without a pair of angles; girdling constriction between abdominal segments III and IV weak to distinct; abdominal sternite III with an anteroventral U-shaped ridge; sting well developed. Differentiation. The worker of Cryptopone is most similar to that of Centromyrmex, but in the latter the basal portion of mandible lacks a distinct circular fovea or elongate depression dorsolaterally. It is also similar in general appearance to that of Ponera and Hypoponera, but in the latter two genera the basal portion of the mandible lacks a distinct circular fovea or elongate depression dorsolaterally, and the dorsal surface of the middle tibia lacks thickened setae. In the worker of Hypoponera the foretibia always lacks a simple spur behind a large pectinate spur (in the worker of Ponera the simple spur is often present but less distinct than in that of Cryptopone). Vietnamese species (5 spp.). C. testacea Emery, 1893. Zry (Cat Tien). C. typhlos (Karavaiev, 1935). Type locality: Cay-Dua, Ins. Phuquoe; Caûda, Cochinchine [Cau Da, Nha Trang]). C. sp. eg-1 [= sp. 8 of SKY in Eguchi, Bui et al. (2005)] (Ba Vi, Sa Pa, Van Ban). C. sp. eg-3 (Pu Mat, Tay Yen Tu). C. sp. eg-4 [= sp. 6 of SKY in Eguchi, Bui et al. (2005)] (Tam Dao, Tay Yen Tu). Bionomics. Cryptopone spp. usually occur in well-developed forests. They nest in rotting logs and wood fragments, under bark of logs, and in litter.

Published as part of Eguchi, Katsuyuki, Viet, Bui Tuan & Yamane, Seiki, 2014, Generic Synopsis of the Formicidae of Vietnam (Insecta: Hymenoptera), Part II — Cerapachyinae, Aenictinae, Dorylinae, Leptanillinae, Amblyoponinae, Ponerinae, Ectatomminae and Proceratiinae, pp. 1-46 in Zootaxa 3860 (1) on page 30, DOI: 10.11646/zootaxa.3860.1.1, http://zenodo.org/record/287059