D1PTERA. 269 



NEMESTRINIDiE (p. 73). 

 EHYNCHOCEPHALUS (p. 73). 



l. Khynchocephalus volaticus. 



Rhynchocephalus volaticus, Willist. Canad. Ent. 1883, p. 71 x ; Trans. Am. Ent. Soc. xiii. p. 293 '\ 

 Rhynchocephalus ?, O. Sack, antea, p. 73 3 . 



To the locality given, add : — United States, Florida l 2 . — Mexico, Chilpancingo in 

 Guerrero (H. II. Smith). 



Three specimens. Osten Sacken's failure to positively identify this species was due 

 to errors in my original description. 



BOMBYLIIDiE (p. 75). 



EXOPROSOPA (p. 77). 

 Exoptata, Coquillett, Canad. Ent. xix. p. 13 (1887). 



Osten Sacken has the merit of being the first to clearly define the genus Exoprosopa, 

 which previously had been made to include all those species with three submarginal 

 cells and a jointed style. The genus might include forms with but two submarginal 

 cells. Unfortunately, the species of Exoprosopa having a brown anterior margin 

 to the wings are not so satisfactorily characterized. Upon first attempting their 

 separation in the collection before me, the task seemed to be an easy one ; further 

 study, however, convinces me that very much mere careful work is needed before 

 we can safely distinguish many of them. 



The genus Exoptata of Coquillett cannot be satisfactorily separated from Exoprosopa. 

 It differs solely in the division of the first posterior cell. The typical species, 

 E. divisa, I have seen from Las Crimes, New Mexico, near the border of Mexico. 

 E. singularis, Macq., has the same peculiarity. 



Table of Species examined for this Supplement. 



1. The pattern of the wings consisting of more or less distinct brown 



bands %. 



No cross-bands on the wings, but a more or less broad brown anterior 

 margin, the cross-veins sometimes clouded 3. 



2. First posterior cell closed, the brown cloud at the base of the second 



posterior cell not connected with the brown in front (length 7-9 



millim.) iota, O. Sack. 



First posterior cell open ; the brown at the base of the second posterior 



cell confluent with that in front pueblensis, Jaenn. 



3. First posterior cell closed or narrowly open 4. 



First posterior ceil distinctly open 6. 



