18 DIPTERA OF NORTH AMERICA. 



Chrysonotus Loew, Sargus Fair., Clorisoma Rond., Chrysc- 

 myia Macq., and Microchrysa Loew. The third section, Herme- 

 tina, is well characterized by the elongated abdomen, the eyes, 

 which are equidistant and very remote in both sexes, and the 

 peculiar structure of the antennas, the third joint of which is 

 transformed into a ciliated lamel. The genera Hermetia Latr., 

 Thorasena Macq. belong to them. The fourth is formed by the 

 Odontomyina, which are distinguished from the foregoing by their 

 broad body and from the following section by the less convex ab- 

 domen and especially by the neuration, the longitudinal veins of 

 the Odontomyina being more crowded anteriorly, the discal cell 

 being smaller, hexagonal or pentagonal, never large or subquad- 

 rate ; moreover, both intercalary veins are usually present, while 

 the posterior one is almost always wanting in the Pachygastrina. 

 The following genera may be referred to the Odontomyina: Cy- 

 phomyia Wied., Chordonota Gerst., Euparyphus Gerst., Pycno- 

 malla Gerst, Alliocera Saund., Stratiomys Geoff., Odontomyia 

 Meig., Inermyia Big., Nemotelus Geoffr., Oxycera Meig., Hete- 

 roxycera Big., Ephippium Latr., Clitellaria Meig., Cyclogas- 

 TER Macq. (= Lasiopa Brull.), Artemida Walk., Aissa Walk., 

 Metabasis Walk., Promeranisa Walk. The fifth section is that 

 of the Pachygastrina; it is distinguished by the longitudinal veins 

 being less crowded towards the costal border, by the magnitude 

 and quadrangular form of the discal cell, the almost general want 

 of the posterior intercalary vein, the short, generally much inflated, 

 abdomen, and its segments soldered together in some genera. The 

 genera belonging here are : Pachyg aster Meig., Loviioteles Loew, 

 Sternobrithes Loew, Platyna Wied., Biastes Walk., Ptilocera 

 Wied., Chauna Loew, Blastocera Gerst, Spyridopa Gerst, 

 Panacrts Gerst., Nerua Walk., Culctja Walk., Evaza Walk., 

 Anacanthella Macq.; perhaps also Phyllophora Macq., and 

 Anisophysa Macq. 



To which section of the Stratiomyidce the genera Solva, Amp- 

 salis, Tracana, Rosapha, Tinda, Saruga, Gabaza, Adraga, and 

 Obrapa, lately formed by Walker, are to be referred, the extreme 

 vagueness of the characters ascribed to them does not allow me to 

 determine. 



The N. A. species which are now known to me belong to the 

 following genera: I. Beridina: Metoponia, Actina ; II. Sargi- 



