Phthirocoris Enderlein, 1904, Zool Anz., 27:783, 785, 786; 1909, Deutsche Südpolar-Expedition, 10, Zoologie (2): 403. Jeannel, 1942, Ann. Soc. ent. Fr (1941), 110 (4): 317–321. Poisson, 1951, in Grassé (ed.), Traité de Zoologie, 10 (2). 1778–1779.

Henicocephalus Westwood, emend. Agassiz, partim, Breddin, 1905, Mitt. Naturh, Mus., Hamburg, 22: 142. Bergroth, 1906, Wien. ent. Zeit., 25: 6; 1906, Ann. Mus. Nat. Hung., 4: 326.

Systelloderes Blanchard, partim, Bergroth, 1916, Proc. Roy. Soc. Vict, 29 (1). 17 Type Species. Phthirocoris antarcticus Enderlein, 1904, Zool. Anz., 27: 787. Fig. 2–5 (nymphs); 1909, Deut. Südp.-Exped., 10, Zoologie (2) 404–406; pl 54, figs. 163–166; text-fig. O-R (adult and nymphs). Jeannel, 1942, Ann. Soc. ent. Fr (1941), 110 (4): 321; fig. 28–33 (including genitalia).

Small, flightless Enicocephalinae, with wings absent or vestigial; head, thorax and appendages shining; with a covering of fine, pale hairs longest at apex of abdomen. Head less than half as wide across eyes as long, behind eyes with a more or less distinct dorsal transverse impression; anterior lobe long and subcylindrical; postocular lobe more or less globose or ovoid, with dorsal surface convex, ventral surface at base more or less swollen beyond level of “neck”. Eyes very small, scarcely prominent, each with only a few ommatidia (2–15). Ocelli absent Antennae subequal in length to head and pronotum together; first segment shortest, other segments subequal in length, fourth fusiform, segments with bases constricted as small subsegments Rostrum with third segment more or less thickened, less than three times as long as second, fourth subequal in length to second Labrum elongate triangular. Pronotum unarmed, three-lobed; anterior and posterior margins straight or nearly straight; anterior lobe fairly large, either rather indefinitely delimited behind or separated by a distinct constriction; middle lobe the longest and widest, roughly hexagonal, with sides convex, widest near the middle; posterior lobe short, its constriction more or less obscure, tending to obsolescence in middle; middle lobe with a median longitudinal impression and with a pair of more or less well defined sublateral foveae Scutellum not defined or short and obscurely delimited. Meso- and meta-thorax short, transverse Mesoscutum more or less convex. Metanotum with disc nearly flat. Wings either entirely lacking or fore wings represented by narrow, elongate, ribbon-like vestiges, with no trace of venation. Legs short. Fore legs strongly incrassate; proepimera not meeting behind fore coxae, leaving front coxal cavities open behind; front coxae globose; front femora much swollen, dorsal surface strongly convex; front tibiae short, gradually increasing in depth towards apex, which bears a pecten along anterior (inner) margin and a ventral group of seven spines