28 PROCEEDINGS OF THE NATIONAL MUSEUM roL. 69 



DisMhution,. — District of Columbia : Piney Branch, April 1, 



1906 (D. H. Clemens). 

 Maryland : Plummers Ishind, April 22-August 28, 



1902-05 (Schwarz and Barber). 

 Minnesota: St. Paul, July 22-Augiist 15, 1901 



(O. A. Johannsen). 

 New York: Ithaca, September 2, 1888 (L. O. 



Howard). 

 Virginia: Rosslyn, July 7-October 5, 1912 (J. R. 



Malloch); September 22, 1911 (I^ab and Mal- 



loch). Great Falls, May 30, 1914 (A. W. Job- 



bins-Pomeroy ) . 



SIMULIUM HYDATIONIS, new species 



Male hypopygium : Side-piece very short conical, twice as wide as 

 long, clasper rather long, stout, elbowed at basal third, the expansion 

 finely pilose; tip of clasper rounded, without spine. Adminiculum 

 broad, membranous, transverse, arched, pilose, the stili short, stout, 

 directed basally. Arms with very fine long teeth, resembling fimbriae 

 in the folds, the sides narrow, lateral plates large. 



Type locality. — Dead Run. Va. 



Type.— Mfile, No. 28340, U.S.N.M. 



Dutrihufion. — Virginia: Dead Run, May 21, 1914 (R. C. Shan- 

 non). 



SIMULIUM VITTATUM Zetterstedt 



Svniulium vUtuUim Zetteestedt, Ins. Lappoii. Dipt., 1835, p. 803. 

 8imulium trihulatum LxJGGEai, 2d rept. Ent. Minn., 1896, p. 205. 

 Simuliuin glaucum Coquillett, Proc. U. S. Nat. Mus.. vol. 25, 1903, p. 97. 

 Siniulkwt dalilgrimi Endehlein. Deut. Tiernrz. Woch. Hanover, 1921, p. 

 43 ; Zool. Auz. vol. 53, p. 45. 



Frons and fore coxae dark opaque gray; thorax with five vittae; 

 abdomen pollinose gray, with three rather indefinite dorsal rows of 

 longitudinal black spots; fore tibia yellowish with a large patch 

 of white pollen ; claws simple. Hypopygium, cerci rounded quadrate, 

 infuscated, setose; anal lobe broad, infuscated and sparsely setose 

 above, slightly lobed below cerci, roundedly expanded ventrally, 

 clear and finely pilose. Genital rod with the arms wide, slender at 

 tip, quadrately expanded, the outer edge of the expansion chitinized 

 and cuneiform, inner widening membranous, apical Avidening trian- 

 gvdar, infuscated. (figs. 74 and 75.) 



Male hypopygium : Side-piece quadrate, longer than wide, with 

 outer basal projection. Clasper stout, truncate, with three terminal 

 teeth; adminiculum broad, membranous, the basal arms short with 

 irregular tijjs ; adminiculum arms with thickened edge and group of 



