254 NORTH AMERICAN FAUNA. [No. 7. 



black, the distal part of the femora, base of tibiae, and the grer.ter part of the me- 

 tatarsi light yellow. Wings pure hyaline, the veins light colored, those posteriorly 

 very delicate. Length, 2-J- mm . 



One specimen, Argus Mountains, Calif., May, 1891. 

 Psilocephala n. sp.? 



A single male specimen. Panamint Valley, April. 

 Thereva vialis Osten Sacken, Western Dipt., 274. 



A single male specimen, Death Valley, Calif., April, 1891. 

 Erax aridus sp. [var.] n. 



A single female specimen, considerably larger than the type of E. latnmculns Will, 

 differs from that species in the legs being wholly black, the hair of the face being 

 wholly white, and in the furcation of the third vein taking place opposite, instead 

 of distinctly beyond the base of the second posterior cell. I am not sure till the 

 male is examined, that these differences are specific. The very marked difference in 

 the color of the legs will, however, justify the varietal name. 

 Anthrax n. sp. 



This species, represented by a single specimen from Panamint Valley, I can not 

 identify with any described species. In Coquillett's most recent synopsis, it is 

 brought straight to A. scitula, from which it differs, however, in important particu- 

 lars, aside from the markings of the wings, the figure of which, herewith given, will 

 permit the recognition of the species. 

 Anthrax fenestratoides Coquillett, Trans. Amer. Ent. Soc. xix, 185, 1892. 



A single specimen, agreeing well with the description, from Panamint Valley, 

 Calif. 

 Anthrax (Stonyx) sodom, n. sp. 



Female. — Black, the legs chiefly yellowish. Face produced conically; clothed, 

 like the front, with black pile slightly intermixed with white tomentum. Proboscis 

 not projecting beyond the epistoma. Style of antennae about twice the length of the 

 bulbous portion. Occiput with yellowish tomentum. Mesonotum clothed with white 

 tomentum and sparse, erect, black hairs. Abdomen white tomentose, with a moder- 

 ate amount of black tomentum, and with sparse, erect, long black hairs; the mar- 

 gins of the abdomen with black and white pile. Base of femora somewhat blackish : 

 front tibia? without spinules; front ungues small, the pulvilli apparently wanting. 

 Wings with brown markings, as in the figure. Length 7 mm . 



One specimen, Death Valley, Calif., April, 1891 (Koebele). 

 Anthrax n. sp. 



A single specimen, from Panamint Valley, Calif., seems to belong to a new species. 

 It is taken to be A. {Dipalta) serpentina in Coquillett's table, from which it differs 

 decidedly. The figure herewith given will enable it to be recognized. 

 Aphcebantus vittatus Coquillett, Can. Entom. May, 1886. 



A single specimen from Panamint Valley, Calif., April 21 (Koebele), seems to be 

 this, though the thorax and abdomen do not have a very " vittate " appearance. 

 Argyramceba daphne Osten Sacken, Biol. Centr. Amer. Diptera, i, 104, pi. 11, f. 6, 



1886.— Mexico. 



One male, from Panamint Valley, Calif. It agrees so closely with the description 

 and figure of this species that I believe the determination very probable. It has, 

 however, three submarginal cells in each wing, a fact which sustains Coquillett's 

 objections to the acceptation of Stonyx and Dipalta. 

 Triplasius novus n. sp. 



Male. — Head narrower than the thorax. Eyes broadly contiguous, the facets 

 markedly larger above, but without a dividing line, the posterior orbits with a dis- 

 tinct incision. Antennae inserted close together, slender, second joint short, about 



