THE MYCETOPHIIvID^ OF NORTH AMERICA. 229 



I. Symmerus tristis Loew. 



1869. tristis Loew, Berl. Ent. Zeitschr. XIII. 131. 2. 

 (Plesiastina). 



Female. Length 4.5 to 5 mm. Head fuscous black, vertex 

 and flagellum of the antenna more purely black. Thorax shin- 

 ing fuscous black, pleura and metanotum a little paler. Abdo- 

 men blackish, with black pile, the apical segment and append- 

 ages yellowish. Legs and coxae fuscous, trochanters and the 

 knees pale. Wings (fig. 81) smoky, the petiole of the media 

 shorter than its anterior branch. Halteres black, stem yellow 

 at base. D. C. (Osten Sacken) ; Massachusetts (W. M. 

 Wheeler, col.). 



2. Symmenis Icnis n. n. (not sonata Stephens). 



1890. sonata Giglio-Tos, Boll. Mus. Anat. comp. Torino. V. 



No. 84. (Ditomyia). 



Male. Length about 12 mm. Face, front and palpi pale 

 yellow ; eyes black, pubescent ; 3 ocelli arranged in a transverse 

 row upon a black spot ; antennae yellow, longer than the head 

 and thorax combined, the 6 apical joints black. Thorax yellow, 

 with yellow pile, with 3 vittae confluent posteriorly; pectus and 

 metathorax black; scutellum yellow. Abdomen black, pilose, 

 the first segment wholly and posterior margins of the others 

 yellow. Legs yellow, hind femora fuscous at the base ; the 

 tips of tibiae, and tarsi blackish. Wing slender, longer than the 

 abdomen, with a slender subfuscous transverse fascia which 

 extends from Ri across the crossvein nearly to the posterior 

 margin of the wing following here the course of Cu^. Halteres 

 yellow. 



Female. Smaller ; antennae wholly testaceous, shorter. 

 Abdomen sparsely pilose. Recorded from Orizaba, ]Mexico, 

 by Giglio-Tos. 



3. Syuiincrus bifasciata \\'illiston. 

 1900. bifasciata Williston, Biol. Centr.-Amer. I. 217. 



(Plesiastina). 



Male. Length 6l-y mm. Head yellow, the ocelli on small 



blackish spots; antennae longer than the head and thorax 



together, light yellow, the last seven joints black, the flagellum 



flattened. Mcsonotum light yellow, with three broad shining 



