98 PROCEEDINGS OF THE NATIONAL MUSEUM vol. GS 



fourth abdominal segment. Genitalia in repose concealed within 

 fourth abdominal segment so that apex is barely visible in lateral 

 view; claws of inner forceps rounded and widely divergent from near 

 base, in profile view, bent backward at middle and slightly forward 

 at tip ; outer forceps much stouter than inner pair, tapering gradually 

 to spoonlike tips; penis with a black, heavily chitinized, S-shaped 

 process on anterior part of hood. Pulvilli not more than half as 

 long as last tarsal joint. Otherwise resembling the female. 



Length, 4.5 mm. 



Type. — In the University of Kansas Museum. 



Range. — New York, New Jersey, Virginia, Ohio, Illinois, Missis- 

 sippi, Florida, Kansas, New Mexico. 



Host relationships. — Unknown. 



Redescribed from the type, a female from southern Florida (Rob- 

 ertson) ; a male from the same locality (Robertson), and several other 

 specimens in the University of Kansas Museum, the National 

 Museum, the Museimi of Comparative Zoology of Cambridge, 

 Massachusetts, and the collections of Prof. J. S. Hine and the writer, 

 from the following localities: one male, Baldwin, Kansas; one female, 

 southern Illinois (Robertson) ; one female. Wild Horse Canyon, 

 Animas Mountains, New Mexico, 5,000 feet; one female, Rosslyn, 

 Virginia, May 1, 1913 (R. C. Shannon) ; one female, Woodbury, New 

 Jersey; one female and two males from Falls Church, Virginia, 

 the males from the honeydew of tulip-tree; one female, Ithica, New 

 York, August 11, 1905 (H. E. Smith); one female. West Point, 

 Mississippi, May 15, 1921 (H. W. Allen); one male, Agricultural 

 and Mechanical College, Mississippi, April 2, 1921 (H. W. Allen) ; one 

 male, Columbus, Ohio. 



Townsend's type for G. darifrons which is a male from southern 

 Illinois, corresponds in all distinguishable characters with the type 

 female of polita which is from southern Florida. 



GYMNOPROSOPA ARGENTIFRONS Townsend 



Gymnoprospa argentifrons Townsend, Trans. Amer. Ent. Soc, vol. 19, 

 p. 109, 1892.— CoQUiLLETT, U. S. Bur. Ent., Tech. Ser., No. 7, p. 129, 

 1897, equals Hilarella polita. — Aldrich, Cat. N. A. Dipt., p. 447, 1905, 

 equals Hilarella polita. 



Male. — Front at narrowest 0.34 of head width (measurements of 

 four 0.32, 0.33, 0.33, and 0.37, respectively) ; frontal vitta divergent 

 from base of antennae, at most only sighsly wider at middle than at 

 vertex, red, sometimes overlaid with silvery pollen, two to four times 

 as wide as parafrontal at lowest orbitals; five to seven bristles in 

 frontal row; one reclinate and two proclinate orbital bristles; no 

 hairs on front outside of frontal rows; face silvery; antennae black, 

 extending seven-eighths distance from base to vibrissae; third joint 



