14 PROCEEDINGS OF THE NATIONAI. MUSEUM. vol. 63. 



Genus MEDETERUS Fischer. 



Medeterus Fischer von Waldheim, Notice sur une Mouche carnivore, p. 10, 

 Moscow, 1819.— Meigen, Syst. Beschr.. vol. 4, p. 59, 1824.— Loew, Smiths. Misc. 

 Colls., No. 171, 1864, pp. 218-220.- Kowakz, Verh. Zool-Bot. Ges., vol. 27, 

 1877, pp. 39-76.— Wheeler, proc. Calif. Acad. Sci., vol. 2, pp. 20-29, 1899.— 

 Aldrich, Kansas Univ. Sci. Bull., vol. 1, p. 91, 1902. — Van Duzee, Proc. Calif. 

 Acad. Sci., vol. 9, pp. 257-270, 1919. 



MEDETERUS VIDUUS Wheeler. 



Medeterus viduus Wheeler, Proc. Calif. Acad. Sci., vol. 2, p. 24, 1899. 



This was described from the State of Washington. A female 

 taken at Healy, Alaska, July 7, no doubt is this species. It differs 

 but little from the description of the single male specimen that 

 Wheeler had. The long yellow hair on the hind tibiae mentioned 

 by him are not found in this female, but there are short yellow 

 hairs on the whole inner surface of the hind tibiae and tarsi. The 

 last section of the fifth vein is only a little longer than the cross- 

 vein, not one and a half times as long. Otherwise it agrees with 

 Doctor Wheeler's description. I think there is no doubt of the 

 determination, 



MEDETERUS DISTINCTUS Van Duzee. 



Medeterus distinctus Van Duzee, Proc. Calif. Acad. Sci., vol. 9, p. 266, 1919. 



Two males and six females were taken at Anchorage, Alaska, June 

 10; one male at Seward, Alaska, June 25, and three males at Healy, 

 Alaska, June 26. I can not separate these from our specimens taken 

 in New York and New Jersej^, one of which is the type of the species ; 

 the eastern specimens are females. 



The male has the hypopygium pedunculate, rather long but not 

 large, all its appendages are yellow, slender, and rather long; there 

 are more or less black hairs on the dorsum of the abdomen. These 

 males are from 2-3 mm. in length ; the vittae on the thorax are less 

 distinct than in the type, especially in the males. 



Genus THRYPTICUS Gerstaecker. 



Thrypticus Gerstaecker, Stett. Ent. Zeit., vol. 25, p. 43, 1864. 



Aphantotimus Wheeler, Psyche, vol. 5, p. 375, 1890. 



Xanthotricha Aldrich, Trans. Ent. Soc. London, 1896, pt. 3, pp. 339-340. 



Thrypticus Gerstaecker, Aldrich, Ent. News, vol. 9, p. 532, 189S; Biologia 



Cent. Amer., Diptera, vol. 1, p. 349, 1901.— Wheeler, Proc. Calif. Acad. Sci., vol. 



2, p. 30, 1899.— Van Duzee, Ps.vche, vol. 22, pp. 84-87, 1915; Psyche, vol. 28. pp. 



124-126, 1921. 



THRYPTICUS FRATERCULUS Wheeler. 



Aphantotimus fraterculus Wheeler, Psyche, vol. 5, p. 379, 1890. 



Thrypticus fraterculus Wheeler, Proc. Calif. Acad. Sci., vol. 2, p. 31, 1899. — 

 Aldrich, Bioloj:;ia Cent. Anier., Diptera, vol. 1, p. 349, 1901.— A'an Duzee, Psyche, 

 vol. 22, p. 84, 1915. 



One female was taken at Fairbanks July 3. Described from Wis- 

 consin ; reported as taken in Ontario, the United States, and Mexico. 



