206 PROCEEDINGS OF THE NATIONAL MUSEUM vol.84 



In the first reference above, Robineau-Desvoidy described four 

 genera, Phorostoma (p. 326), Myostoma (p. 327), Billaea (p. 328), 

 and Myocera (p. 328). In his 18G3 paper he stated that the geno- 

 types of the first and last named were specifically identical. He said 

 that his male of suhrotunda^ sole species of Phorostoma^ and his 

 longipes female, first-named species of Myocera^ were synonyms of 

 ferina Fallen. In the original descriptions, Phorostoma^ Myostoma^ 

 and Billaea are said to be much alike, differing mainly in the position 

 and shape of the antennae. Myocera is said to be analogous to the 

 other three in the original description, and the apical ceil is said to 

 be open in the apex of the wing. 



In the latter work it becomes obvious that Phorostoma and Myocera 

 are alike, and the supposition can only be that all four are essentially 

 similar. 



MYOCERA TABANIVORA, new species ^ 

 J"^GURE 21 



Male. — Head with front very narrow, about 0.011 of head width 

 in the single specimen; frontal stripe dark, less than one parafrontal 

 in width at narrowest point just below ocelli, but widening grad- 

 ually to fully four times this width anteriorly; parafrontals black 

 with thin gray pollinosity; frontal bristles about eight, the rows 

 diverging but slightly below and descending to about the base of 

 second antennal segment; a few" short bristlelike hairs situated be- 

 tween the frontals; parafacials bare, golden pollinose over the black 

 ground color; facial ridges without ascending bristles; antennae 

 black, third segment about one and one-half times the length of 

 second, descending only to about the lower third of clypeus; arista 

 short, about as long as second and third antennal segments together, 

 yellowish at middle, short-plumose both above and below to tip, 

 penultimate segment short; a well-developed facial carina descend- 

 ing to lower third of clypeus; vibrissae above the oral margin by 

 about the length of the second antennal segment; epistoma pro- 

 tuberant; epistomal and antennal axes approximately equal; bucca 

 about one-fourth eye height, with black hair; palpus elongate, slen- 

 der, rather yellowish; proboscis hardly longer than buccal length; 

 eye bare, oblique; back of head with one and a partial second row 

 of postocular ciliae, the middle and below with black hairs, below 

 with some hair; ocellar bristles proclinate, well defined; outer orbital 

 bristles absent; vertical bristles distinct; outer vertical bristles not 

 differentiated from surrounding setae. 



Thorax black with dorsal stripes poorly differentiated by slight 

 silvery pollinosity ; humeral bristles four ; postlateral bristles present 

 in foremost only; anterior dorsocentrals four; anterior acrostichals 



*A description of the pupa of this species by C. T. Greene follows on page 217. 



