212 ERNEST A. BACK. 



not noticeably narrowed at tip, and without style, over two 

 times the length of the first and second segments taken to- 

 gether; on close examination a minute spine will be seen 

 situated a little to one side of the tip of the segment. Face 

 swollen on the oral margin; from thence gradually receding 

 until the antennae are reached; mystax extending nearly to 

 antennas. Thorax normal. Abdomen as in Dizonias; not 

 narrowed toward the tip in the male; somewhat so in the fe- 

 male; genitalia similar to Dizonias, Ceraturgus and Ceratur- 

 gopsis, leaving the end of the abdomen apparently open. 

 Abdomen without bristles except on side of the first segment. 



Type. — Sphageus chalcoproctus Loew. 



The characteristic patches of short bristles on the femora 

 make this a very unique genus. 



Sphageus chalcoproctus. 



Sphageus chalcoproctus Loew, Cent., VII, 55, 1866. 

 $ 9- — Length 19.5 mm. — Head and thorax black; antenna?, angles 

 of thorax, scutellum, abdomen and legs yellowish-red. Face, front, 

 occiput, all the coxae before, spot over each coxa;, before base of wing, 

 the pronotum, and a stripe running backward to the posterior callosities 

 above the dorso-pleural suture, spot behind each humerus, two stripes 

 in front of the scutellum attenuated anteriorly, the scutellum, except 

 spot at middle of base and a spot above each halter, all golden 

 pruinose. Mystax extending upward nearly to the antennae; pile and 

 bristles of head, thorax and abdomen wholly golden. Anterior angles 

 of segments 2-4 of the abdomen with a white pruinose spot reaching 

 backward to the posterior angle; all the segments with a narrow black 

 posterior margin; fifth segment of the female with a brilliant metallic 

 purplish luster; male genitalia reddish with golden hair. Legs reddish- 

 yellow, bristles of the characteristic patches black; rest of bristles 

 black and yellow; claws black, reddish at base. Wings yellowish; 

 the discal, second submarginal, all the posterior, the anal and the 

 axillary cell lighter in the center. 



Type. — M. C. Z. A single male and female specimen. 

 Habitat. — Cuba. 



MICROSTYLUM. 



Microstylum Macquart, Dipt. Exot., I, pt. 2. 26, 1838. 

 Microstylum Loew, Dipterenfauna Sudafrika's, 74, 1860. 

 Megapollyon Walker. 

 Megapollyon Bigot, Annales, V, 548, 1857 (table of genera). 



Large species. Proboscis longer than the height of the 

 head; wings of ordinary length and narrowness, first posterior 



