OF THE TABANID^ OF THE UNITED STATES. 393 



Hah. Cambridge, Mass.; S. Amherst, Mass. (G. Dimmock); Tarrytown, N. Y. ; Dela- 

 ware ; Maryland. Twelve female and two male specimens. 



Two female specimens which I took at the Trenton Falls, N. Y., in July, 1874, have 

 black frontal tubercles, and the feet more black tlian usual. I hardly doubt the specific 

 identity of these specimens. 



23. Chiysops obsoletus Wiod. 



C/iri/sops obsoletus Wiedemann, Dipt. Exot., i, p. 108, 10 ; Auss. Zweifl., i, p. 211. 



?. Tiie liyaline triangle sejiarating tlie crossband from the a]iieal spot reaches the costa ; both basal cells 

 hyaline ; abdomen broiou, with a yellow, tapering, median stnpe, ichich does not reach the tip, and tu-o lateral 

 narruicer, and still nwre abhrevietted stripes. 

 Length, C.5-8 mm. 



Female. Antennae black ; more or less yellowish at the base ; face 3-ellowisli-ferruginous, 

 facial callosities black ; front yellowish-gray, wdth a large, black callosity. Thorax with the 

 usual greenish-gray median stripe, divided by a black line ; yellowish lateral stripes and yel- 

 low stripes on the pleuro3. Abdomen more or less dark brown ; a yellow stripe, tapering 

 posteriorly, reaches from the base of the first segment to the hind margin of the fourth or 

 even the fifth segment ; two lateral, narrower, yellow stripes on the first and a portion of 

 the second, sometimes even on the third and fourth segments. Venter brown, with more 

 or less yellow on the sides of the first three segments ; a brown lateral stripe often crosses 

 the yellow. Legs reddish, with the end of the front tibiae and the front tarsi, the ends of 

 the four posterior tarsi, the base of the hind femora, etc., black. Wings: two basal, anal, 

 fifth posterior cells and anal angle hyaline ; crossband almost reaching the hind margin 

 along the vein between the third and fourth posterior cells, but leaving a hj-aline space on 

 the proximal end of the discal cell and, in the fifth posterior cell, along the intercalary vein. 

 The hyaline triangle between the crossband and the apical spot crosses the second longitudi- 

 nal vein, and touches the costa ; the apical spot is of a paler shade of brown than the cross- 

 band and evanescent posteriorly. 



Hah. Pennsjdvania ; Maryland; Manlius, N. Y. (J. II. Comstock) ; Cambridge, Mass. 

 (Sept. 19); North Conway, N. II. (Augu.st, 1874). Nine females. 



In some specimens the lateral stripes of the aljdomen become obsolete; in others, on the 

 contrary, a trace of a prolongation is visible on the third and fourth segments. Wiedemann 

 mentions a specimen from Pennsylvania, in which tliese stripes almost reached the end of 

 the abdomen. Sometimes the brown tiuge of the costal cell is very pale. 



The male of this species, according to Wiedemann, has no stripes, either on the thorax or 

 on the abdomen. 



24. Chrysops plangens Wied. 



Chri/sops plan (/ens Wie;lemann, Auss. Zweifl., i, p. 210, 22 ( $ ). 



C/tri/sops fuli(/inosus Wiedemann, Dipt. Exot., i, p. 109, 11 ; Auss. Zweifl., i, p. 210, 23 ( 5 ). 

 ? . Tlie apical sjiot is separated from the crossband by a hy.alinc lunule, reaching to the costa; first basal 

 cell infuscated ; the brown design on the wing is rather pale ; body altogether grayish. 

 $ . Altogether blackish; wings pale brownish, with some faint paler streaks. 

 Length $ , G-8.5 mm. ^, , C.5 nnn. 



Female. Head gray ; face ferruginous in the middle, with black, shining frontal callosi- 

 ties, separated from the black, shining cheeks by a stripe of yellowish pollen; antennce 



MU.HOIUS BOST. SOC. NAT. Ill ,T. VOL It. 



