522 



3. Scutellum yellow, remainder of thorax black ; cross vein not at rigrht 



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

 eral arm of hypopygiuni as in Figure 10, Plate XL 



3. flavoscutellatus. 



— Scutellum coneolorous with mesonotum, or but little paler; cross 



vein almost at right angles to first vein 4 



4. Halteres pale yellow 5 



— Halteres brown or blackish 6 



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



(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 tibige; 



hypopygiuni 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 SUBPARALtELUS, n. sp. 



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

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

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

 brown. Wings slightly grayish, veins brow^n. 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. Tliird vein ending much in front of apex of 

 wing; cross vein subparallel w^ith 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, 191 4, on bank of Mis- 

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



Female and early stages unknown. 



2. Orthocladius pilipes, n. sp. 



Male. — Differs in color from suhparalleliis 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, witli a narrow but distinct central dorsal 

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

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



