June-Sept., 1919-] ALEXANDER: NEOTROPICAL CRANE-FLIES. 141 



2. Mongoma Westwood (type fragillima (Westw.)). 



3. Paramongoma Brunetti (type albitarsis (Dol.)); syn. Mongomella 



Enderlein (type pallida (Will.)). 



4. Neomongoma, new (type disjuncta (Alex.)). 



These groups may be separated by the following key: 



1. Vein and cell M 3 present (t. e., 4 posterior cells) 2 



Vein and cell M 3 lacking (/. e., 3 posterior cells) 3 



2. Cell Cu widely open at the wing-margin (New World) . .Neomongoma new. 

 Cell Cu closed by the fusion of Cn 2 and 1st A at the wing-margin (Old 



World) Mongoma Westwood. 



3. Cell 1st M. 2 open by the atrophy of m ; cell Cu closed by the fusion of 



Cu 2 and 1st A at the wing margin (Old World) ... .Trentepohlia Bigot. 

 Cell 1st M 2 closed ; cell Cu open at the wing-margin (mostly New 



World; one species in Java) Paramongoma Brunetti. 



Trentepohlia (Paramongoma) albitarsis (Dol.) of Java. 



This is a very rare species that has apparently not been found 

 since its original discovery. To judge from Brunetti's recharacter- 

 ization of the insect it agrees well with the Neotropical species of 

 the subgenus except that the sector continues to the inner angle of 

 cell 1st M 2 obliterating the deflection of vein R i+i . 



The most generalized member of the genus so far made known 

 is T. disjuncta (Alex.) ; the most specialized are species of the sub- 

 genus Trentepohlia of the gracilis group (gracilis (End.), zambezice 

 (Alex.), nigroapicalis (Brum), etc.). 



Trentepohlia (Paramongoma) sororcula new species. 



General coloration light brown, tibiae broadly white at the tips ; all the 

 tarsi white ; wings with the stigma pale. 



Male. — Length, 7 mm.; wing, 6.2 mm.; hind leg, femur, 11.3 mm.; tibia, 

 1 1.7 mm. 



Female. — Length, 8.6 mm.; wing, 6.3 mm.; fore leg, femur, 10.2 mm.; 

 tibia, 1 1.4 mm. 



Rostrum and palpi brown. Antennae dark brown, the flagellar segments 

 almost cylindrical and rather elongate. Head brown. 



Thorax shiny light brown, the pleura slightly more yellowish. Halteres 

 short, brown. Legs with the coxae and trochanters yellowish ; femora light 

 brownish-yellow, the tips narrowly (.6-. 9 mm.) white; tibiae with a white 

 basal band that is subequal to or a little narrower than the apical ring of 

 the femur; remainder of the tibiae brown except the broad (3.3-4 mm.) white 

 tips; tarsi white. Wings with a slight yellowish tinge; stigma small, rounded, 

 pale brown; veins dark brown. Venation (Plate I, Fig. 15): basal deflection 

 of Cu 1 just before the fork of M. 



