DASYPOGONINtE 



709 



says it is distinguished by its " stouter body, thicker mystax, shorter 

 *• wings and some other peculiarities." The " other peculiarities " may 

 include a peculiar plate-like process at the end of the middle tibiai, 

 which occurs in some very large species. 



MlCROSTYLUM. 



12 (11) Second posterior cell almost level with the upper part of the 



discal cell (fig. 376). 



Third veinlet from the discal cell (even when closing the fourth 

 posterior cell) not long and parallel with the wingmargin. 



13 (16) Metapleurae quite bare. First posterior cell closed or obviously- 



contracted towards the wingmargin (rarely only slightly so). 



Thorax with numerous bristles extending from the prsesutural 

 down the sides and across the hindmargin. Head usually narrower 

 than the thorax and inclined to be spherical ; face narrow and 

 becoming still narrower on its upper part, with a prominent almost 

 keel-shaped knob. Alulae large. Alar squamae bearing a tuft of long 

 hairs. Large or rather large flies. 



14 (15) First posterior cell open (fig. 376). 



Fig. 376. — Stenopogon xanthotrichus <J. x 6. 



Fourth posterior cell either open or closed. Similar to Scleropogon 

 (sensu meo), but the third antennal joint longer and its style shorter. 

 Hypopleurse quite bare. 



Stenopogon. 

 15 (14) First posterior cell closed (fig. 377). 



PiQ. 377. — Scleropogon heteroneurus ?. x 5. 



Fourth^ posterior cell closed. Similar to Stenopogon, but the third 

 antennal joint shorter and its style longer. 



Scleropogon. 



N.B. 1 . — The figure given here is taken from the (probable) 

 original type of Dasjipogon heteroiuuriis Macquart, and differs from 

 Loew's description of Scleropogon in having the second posterior cell 

 closed as well as the first and fourth. 



A^.i?. 2.— Coquillett (Pr. Ent. Soc. Wash., vi., 179, 1904) states that 

 Scleropogon has the hypopleurse pubescent and bristly ; if that be the 



