16 PROCEEDINGS OF THE NATIONAL, MUSEUM. vol.63. 



tarsi with the fourth joint shorter than fifth. Calypters and their 

 cilia yellow. Halteres brown, their stem paler. 



Wings grayish, tinged with brownish in front of fourth vein and 

 along the cross- vein, without spots on fourth vein or cross- vein; 

 third vein bent backward a little at tip; last section of fourth vein 

 straight, ending back of tlie apex of the wing; last section of fifth 

 vein a little more than half as long as the cross-vein. 



Described from one male taken at Fairbanks, Alaska, July 1. 



ry;?e.— Male, Cat. No. 25963, U.S.N.M. 



Genus HERCOSTOMUS Loew. 



Ilercostomvs Loew, Neue Beitr., vol. 5, p. 9, 1857 ; vol. 8, p. 42, 1861 ; Smiths. 

 Misc. Colls.. No. 171, p. 116, 1864.— Wheeler, I'roe. Calif. Acad. ScL, vol. 2, p. 8, 

 1899.— Melandek, Canadian Ent., vol. 32, p. 138, 1900. 



HERCOSTOMUS UNICOLGR Loew. 



Hercostoiiius itnicolor Loew, Smiths. Misc. Colla, No. 171, p. 117, 1864. — 

 Melander, Canadian Ent, vol. 32, p. 138, 1900. 



Gymnopternus poenitens Wheeler, Psyche, vol. 5, p. 336, 1890. 



One female was taken at Healy, Alaska, June 27. Described from 

 the " Hudson Bay Terr." It is found all over Canada and the north- 

 ern part of the United States. 



Genus PELASTONEURUS Loew. 



Pelast&neurus Loew, Neue Beitr.. vol. 8, p. 36, 1861 ; Smiths. Misc. Colls., No. 

 171, pp. 103-109; 337-339, 1864.— Wheeler, Proc. Calif. Acad. Sci., vol. 2, pp. 

 11-17, 1899.— Aldrich, Biologia Cent. Amer.. Diplera, vol. 1, pp. 336-339; 

 Trans. Amer. Ent. Soc, vol. 30, pp. 273-278, 1804. 



PELASTONEURUS VAGANS Loew. 



Pelastoneurus vagans Loew, Neue Beitr., vol. 8, p. 39, 1861 ; Smiths. Misc. 

 Colls., No. 171, p. 107, 1864. 



One male was taken at Anchorage, Alaska, July 19. Described 

 from the " Middle States "; found all over the United States, Canada, 

 and Mexico. 



EXPLANATION OF PLATE. 



Fig. 1. Nothosympycnus cilifemoratus, new species, fore tarsus of male. 



2. Antenna of same. 



3. Campsicnemus americanus, new species, fore leg of m^ile. 



4. Campsicnemus calcaratus, new species, middle leg of male. 



5. Campsicnemus americanus, new species, antenna of male. 



6. Campsicnemus calcaratus, new species, antenna of male. 



7. I'orphyrops alMharha, new species, antenna of male. 



8. Porphyrops terminaUs, new species, antenna of male. 



9. Porphyrops nudus, new species, outer hypopyginal lamella of male. 



10. Porphyrops alhibarha, new species, hypopj'gium of male. 



11. Porphyrops terminaUs, new species, hypopygiura of male. 



12. HydropJiorus mini?nus, new species, fore femora of male. 



