168. THRESSA SIGNIFERA, n. s. _Foem._ Nigra, nitens, capite cyaneo, antennis pedibusque fulvis, thorace strigis duabus lateralibus albis, femoribus nigris, alis hyalinis apud costam nigris, halteribus albis. _Var. β._ Alis apud costam hyalinis macula apicali nigra. _Female._ Black, shining; head blue; antennæ tawny; thorax with a white transverse streak on each side; legs tawny; femora black, with tawny tips; wings hyaline, black along the costa; veins black; discal transverse vein parted by four times its length from the border, and by six times its length from the præbrachial transverse; halteres white. _Var. β._ Wings not black along the costa, with the exception of a black apical spot. Length of the body 1-1/2 line; of the wings 2-1/2 lines. Gen. OCHTHIPHILA, _Fallen_. 169. OCHTHIPHILA DISCOGLAUCA, n. s. _Foem._ Fusca, capite thoracisque disco glucescente-albidis, arista plumosa, thorace lineis duabus lateralibus albidis, abdomine lineis transversis vittaque albidis, tibiis tarsisque rufescentibus, alis cinereis, halteribus testaceis. _Female._ Brown; head glaucous-whitish; antennæ black, nearly reaching the epistoma; third joint conical, arista plumose; thorax with a very broad glaucous-whitish stripe, a whitish line on each side and two on each side of the pectus; abdomen oval, a little shorter than the thorax, with a whitish band on the hind border of each segment and with a whitish stripe, the whitish hue appearing tawny in some aspects; tibiæ and tarsi reddish; wings gray; veins black; discal transverse vein straight, upright, parted by much less than its length from the border, and by nearly twice its length from the præbrachial transverse; halteres testaceous. Length of the body 2 lines; of the wings 4 lines. Gen. CELYPHUS, _Dalman_. 170. Celyphus obtectus, _Dalman_. See Vol. I. p. 30. 171. Celyphus scutatus, _Wied._ See Vol. I. p. 131. Subfam. ORTALIDES, _Haliday_. Gen. LAMPROGASTER, _Macq._ 172. Lamprogaster marginifera, _Walk._ See Vol. II. p. 111. Gen. PTEROGENIA _Bigot_, MSS. _Mas et Foem. Platystomati_ affinis. _Corpus_ breve, latum, crassum, Caput thorace latius, antice planum, genis dilatatis. _Antennæ_ parvæ; articulus 3^{us} longi-conicus; arista plumosa. _Thorax_ subconvexus; scutellum magnum. _Abdomen_ thorace brevius et angustius. _Pedes_ breves, validi; tibiæ arcuatæ. _Alæ_ sat parvæ; alulæ maximæ. _Mas._ Genæ angulatæ, valde dilatatæ. This genus is allied to _Platystoma_ and more especially to _Trigonosoma_.