390 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.58. 



Genus BITTACOMORPHELLA Alexander. 



BITTACOMORPHELLA JONESI Johnson. 



The pygmy phantom crane-fly is a very local species. The curious 

 short black larva lies in rich organic mud in cold woods. This 

 species has been taken at Glencarlyn, Virginia, by Nathan Banks. 



Genus BITTACOMORPHA Westwood. 



BITTACOMORPHA CLAVIPES Fabricius. 



The phantom crane-fly is one of the most common species of the 

 Tipuloidea. The curious rust-brown larvae live in organic matter 

 and mud in open swamps and swales. Adults have been collected in 

 all parts of the Washington region, at dates ranging from April 6 

 to October 8 ; in copulation, April 12, October 8. The species is at- 

 tracted at light. V. P. I. 



Family RHYPHIDAE. 



KEY TO GENERA. 



1. Cell 1st M2 lacking Mycctobia (p. 390). 



Cell 1st M2 present 2. 



2. A single anal vein; two branches of the radial sector reaching the wing 



margin Rhyphus (p. 390). 



Two anal veins; three branches of the radial sector reaching the wing 

 margin Trichocera (p. 391) 



Genus MYCETOBIA Meigen. 



MYCETOBIA PERSICAE Riley. 



Numerous specimens bred from gum and frass from around bases 

 of peach trees where the peach-tree borer had been working, Arling- 

 ton, Virginia, October, 1915, W. B. Wood. 



Genus RHYPHUS Latreille. 



KEY TO SPECIES. 



1. The two veins that form the outer end of cell First M2 subequal, or the basal 



deflection of M2 longer than m; a faint yellowish blotch at the end of Sc; 



brown wing markings exteu.sive, including the wing apex 2. 



The basal deflection of M2 usually punctiform, much shorter than m; no 

 yellowish blotch at the end of Sc; brown wing markings scanty, appearing 

 as about three blotches on the basal two-thirds, the outermost lying at the 

 tip of Ri, the wii'g apex clear R. punctatus. 



2. Wing pattern clear cut, the brown markings extensive; the subapical drop 



white or hyaline, sharply delimited ; r-7n at nearly two-thirds the length 



of cell first M R. alternatus. 



Wing pattern more diffuse, the brown markings less extensive, the subapical 

 drop subhyaline to grayish, not clearly delimited ; r-^m at about one-half 

 the length of cell first M. (Regional) R. fenestralis Scopoll. 



