52 SYNOPSIS OF THE DIPTEROUS 
Species XVI.—M. brevicornis, Wied. (Mon. Mid. pl. 53, f.9.) Niger, politus abdominis 
segmentis 3, 4, flavido-diaphanis. Long. lin. 1]. 2. 
Habitat in Brasilia. 
Obs. 1.—Cellula media marginis postici ramum nullum ad 
marginem posticum currentem emittit. 
Obs. 2.—M. iopterus, Wied. Auss. Zw. Ins. 1. 241. 4. Var. 
differt segmentis 3, 4 abdominis utrinque macula parva sub- 
quadrata flavida notatis et alis ubique fuscis chalybzeo resplen- 
dentibus. 
Species XVII.—M. leucops, Wied. (Mon. Mid. pl. 53, f. 10.) Thorace nigro, vittis 
epistomateque albopilosis, abdomine chalybzxo, alis sinuato-fuscano-flavis. Long. lin. 11 ¢. 
Habitat in Brasilia. 
Species XVIII.—M. gracilis, Macq. (Hist. Nat. Ins. Dipt. 1, p. 274, pl. 7, fig. 1.) Niger, 
barba et frontis lateribus albidis aut flavidis, thorace lineis 4 albis, intermediis duabus 
antice paullo dilatatis, vitta nigra dorsali velutina, lateralibus duabus leevibus brunneis, 
metathorace maculis duabus albis, abdomine violaceo metallico segmento Imo nigro 
albopiloso reliquis fulvo tenuiter marginatis, pedibus nigris femoribus tibiisque posticis 
obscure testaceis, alis brunnescentibus. ¢ 9. Long.corp. lin. 10. 
Habitat in America meridionali. 
Species XIX.—M. ruficornis, Wied. (Mon. Mid. pl. 53, fig. 11.) Niger thorace antice 
melleo-fuscano, antennis ferrugineis alis fuscis. Long. lin. 9. Ex Tranquebar. 
Species XX.—WM. interruptus, Wied. (Mon. Mid. pl. 53, f.12. ¢ Q.) Niger, abdomine 
fasciis tribus flavis; ]ma utrinque interrupta. Long. lin. IJ—10. ¢ 2. 
Habitat in Mexico. 
Srecres XXI.—WM. senilis, Westw. n. sp- Totus niger griseo-setosus, barba epistomatis 
grisea alis fuscanis costa magis fulvescenti venis posticis fusco-marginatis, cellula media 
versus marginem posticum venam brevemad marginem currentem hand emittenti. Long. 
corp. lin. 6. Expans. alar. lin. 16. ’ 
Habitat in Mexico. Tacubayanostr. D. Coffin. Mus. West. 
Species XXII.—M. viduatus, Westw. (in Lond. and Edinb. Phil. Mag., April 1835), 
Pl. 14, fig. 2. Niger, faciei et thoracis lateribus maculaque triangulari ad basin segmento- 
rum 3 et 4 abdominis sericie argentea obsitis, alis pallidis in medio fuscantibus, venis 
fusco marginatis. Long. corp. lin. 10. Exp. alar. lin. 16. 
Habitat in Nova Hollandia. Maus. nostr. 
Obs.—In this, and the two other Australian species of this genus 
described below, the fifth longitudinal vein extends to the costa a 
little before the extremity of the wing, instead of joining the 
extremity of the second longitudinal vein; moreover the long 
closed middle cell near the hind margin of the wing is not 
appendiculated (or petiolated) at its extremity most remote from 
the body, but extends to the next cell, which runs to the tip of 
the wing. 
Species XXIII.— WM. fulvifrons, liger. (Wied. Mon. Mid. pl. 53, fig. 13.) Niger, abdo- 
minis medio flavo, epistomate fulvo-hirto, antennis nigris, clava rubiginosa, alis saturate 
flavidis, pedibus nigris, tibiis subrubido-fuscis. Long. lin. 93. 
Habitat in Georgia Americana. 
Obs.—In the collection of drawings of Georgian insects, made by 
Abbot in the library of the British Museum *, are two figures ; one 
of which I consider to represent this insect. It is numbered 65, 
and represents the first segment of the abdomen as black; the 2nd, 
srd, and 4th, fulvous with a pale hind margin; the 5th with a 
fulvous margin alone; the remaining segments black. 
* Vol. 13, Diptera, Catalogue mark 7956, Plutarch 126 E. 
