COMYOPS. 2638 
Head white; frontal band, antenne, and pilosity of the eyes as in C. nigripennis; vibrisse quite at the oral 
margin; proboscis black, the palpi yellowish-rufous. Thorax black, before the transverse suture with 
whitish tomentum and four black stripes, the median ones linear; on the pleure a whitish stripe extends 
from the shoulders to the middle coxe; scutellum shining black. Abdomen shining black ; second and 
following segments with greyish-white front borders, on the second segment an obsolete black dorsal 
stripe; long macrochete at the hind margins of the segments. Legs asin C. nigripennis. Tegule 
whitish. Wings greyish-hyaline, the apical part of the costa dilute brownish; small cross-vein a little 
beyond the midde of the discal cell; apical and posterior cross-veins oblique and very slightly curved. 
Hab. Mexico, Venta de Zopilote in Guerrero 2800 feet (H. H. Smith). 
A single male specimen. 
The following Central-American species are included by their authors in the group 
Dexine, but have not been noticed in the preceding pages :— 
Megaprosopus rufiventris, Macq. Dipt. Exot. ii. 3, p. 84, t. 10. fig. 1—Mexico. 
Dexia pertecta, Walker, Trans. Ent. Soc. Lond. new ser. v. p. 307.—Mexico. 
Homodexia longicornis, Bigot, Ann. Soc. Ent. Fr. 1888, p. 267. no. 71.—Mexico. 
flavipes, Bigot, 1. c. p. 268. no. 73.—Mexico. 
spinosa, Bigot, l. c. no. 74.—Mexico. 
triangulifera, Bigot, 1. c. no. 75.—Mexico. 
Oplisa albifacies, Bigot, 1. c. no. 76.—Mexico. 
nigrifacies, Bigot, 1. c. no. 77.—Mexico. 
Pyrrosia ochracea (sic), Bigot, 1. c. no. 78.—Mexico. 
Anthracomyia pallidicornis, Bigot, 1. c. p. 270. no. 86.—Mexico. © 
Myiomima sarcophagina, Brauer & v. Bergenst. Denkschr. der kais. Akad. der 
Wissensch. Wien, lvi. pp. 119, 167.—Central America. 
As to the genus Megaprosopus, Macq., it seems doubtful if it belongs to the group 
Dexine, the arista being bare and the frontal bristles descending beneath the root 
of the antennee (see the figure of the head given by Prof. Brauer in Denkschr. der kais. 
Akad. der Wissensch. Wien, lvi. t. 7. fig. 147). 
Dexia pertecta, Walk., also has the arista bare, and therefore its real position is 
uncertain ; at all events, it cannot belong to the genus Dexia in its restricted sense. 
Of the above-mentioned species described by Bigot I have examined typical examples 
kindly communicated by him. 
The genus Homodexia, Big., is very incompletely characterized (Bull. Soc. Ent. Fr. 
1885, p. xxvi), the author stating that “it only differs from Dexiosoma, Rond., by the 
absence of an appendage at the curvature of the fourth vein.” In his synoptic table 
of the genera of Dexine (‘Revue d’Entomologie,’ 1885, p. 266), he adds that “the 
