522 



3. Seutellum yellow, remainder of thorax black ; cross vein not at right 



angles to first vein (PL XXXIX, Fig. 13) ; apical portion of lat- 

 eral arm of hypopygium as in Figure 10, Plate XL 



3. flavoscutellatus. 



— Seutellum coneolorous with mesonotum, or Ijut little paler ; cross 



vein almost at right angles to first vein 4 



4. Halteres pale yellow 5 



— Halteres JDrown or blackish 6 



5. Basal joint of fore tarsi nearly three fourths as long as fore tibia? 



(26 : 35) 4. lacteipennis. 



— Basal joint of fore tarsi two thirds as long as fore tibiae 



5. ohumhratus. 



6. Basal joint of fore tarsi about four fifths as long as fore tibia ; 



hypopygium as in Figure 3, Plate XXXVII 6. nigritus. 



— Basal joint of fore tarsi distinctly less than four fifths as long as 



fore tibiae 7. nivoriundus. 



I. Orthocladius subparalleIvUS, n. sp. 



Male. — Black, slightly shining. Head, including antennae and 

 their plumes, fuscous. Thorax black, disc shining, the membranous 

 portion of pleurae brownish yellow. Legs fuscous, tibiae and tarsi pale 

 brown. Wings slightly grayish, veins brown. Halteres fuscous. 



Eyes bare; palpi 4-jointed. Pronotum of moderate breadth 

 throughout, central dorsal excision broad and distinct ; mesonotum 

 with few discal hairs. Hypopygium as in Figure 6, Plate XL, the pro- 

 jection on inner side of basal portion of lateral arm very weak. Legs 

 slender; fore tarsi without long hairs, basal joint slightly more than 

 half as long as fore tibiae (18: 33) ; mid and hind legs with moder- 

 ately long fine hairs. Third vein ending much in front of apex of 

 wing; cross vein subparallel with first (PI. XXXIX, Fig. 12) ; cubitus 

 forking very slightly beyond apex of cross vein. 



Length, 2.5 mm. 



Type locality, Grand Tower, 111., April 21, 1914, on bank of Mis- 

 sissippi River (C. A. Hart and J. R. Malloch). 



Female and early stages unknown. 



2. Orthocladius piupES, n. sp. 



Male. — Differs in color from snhparalleliis in being less intensely 

 black, and in having distinct grayish pruinescence between the thoracic 

 vittae, and the tibiae but little paler than the femora. 



The pronotum is broad, with a narrow but distinct central dorsal 

 excision, and tlie disc of mesonotum has sparse long hairs. Hypo- 

 pygium as in Figure 8, Plate XXXVII. Fore tarsi with very long 



