OF THE TABANID^ OF THE UNITED STATES. 385 



more or less trapezoidal black spot in the middle ; on the hind margin of the second seg- 

 ment, in the middle of this black spot, a gray triangle is visilile ; the following segments 

 are black, with similar gray triangles in the middle (often very foint) ; hind margins of the 

 segments grayish, becoming yellowish on the sides. In well preserved specimens the 

 gray triangles and the hind margins are Ijeset with a golden-j^ellow pubescence. In 

 some specimens the reddish color on the first two segments occupies much more space, the 

 extent of the black color being smaller in consequence ; in such cases the third and fourth 

 segments also show some reddish on the sides. Venter yellowish at the base, with more or 

 less black in the middle ; the latter half Idack ; hind margins of the segments paler. Legs 

 very variable in coloring, the l>lack color prevailing in some specimens, the red in others. 

 Wings : root, costal cells, proximal half of both basal cells, brown ; the crossband does 

 not reach the posterior margin, the distal end of the fourth posterior cell being more or less 

 hyaline ; the crossband is not limited posteriorly by the intercalary vein, but fills out more 

 or less the proximal end of the fifth posterior and the distal end of the anal cell, where it 

 is fainter ; it even extends, but as a very faint gray tinge, into the anal angle ; the apical 

 spot is coalescent with the crossband in the marginal and first su])marginal cells, which are 

 completely filled out with brown ; the second submarginal cell is brownish on its anterior 

 half only. 



IlaJc. The thorax is more yellowish hairy, and its stripes less apparent; the abdomen is 

 reddish-yellow ; segments 1-4 with black sjiots in the middle, which are broader in front 

 than behind ; they do not reach the hind margins, except the spot on the first segment, 

 which coalesces with that on the second ; segments 5-7 black, with the hind margins yellow. 

 Venter yellow ; first two segments with black spots in the middle ; segments 3 and 4 with a 

 transverse blackish crossband, aljbreviated on both sides ; segments 5-7 Ijlack, with yellow 

 hind margins. Wings as in the female, only the hyaline space at the distal end of both 

 basal cells is smaller, and the prolongation of the crossband in the fifth posterior and anal 

 cells darker. 



I have Ijefore me two male specimens from Massachusetts, which I can only refer to this 

 species, although I have not a single female from this state. 



Hah. Great Slave Lake and Northwestern Regions of the British Possessions (R. Kenni- 

 cott); Saskatchewan (Scudder); Quebeck (Belanger); Sharon Springs, New York. Five fe- 

 males. Two hypothetical males from Massachusetts. 



Among all the Chnjsops with an apical spot on the wings, this species is the only one 

 which is not marked with ferruginous in the middle of the fnce; the coloring of the fiice 

 here is exactly similar to that of the sjaecies of the group A ; in its general appearance, it 

 reminds one of the species of that group. This character renders its recognition very easy. 



15. Chiysops flavidus. 



Chrysops fluvidus Wicdenwnn, Dipt. Exot., i, 105, 5. Auss. Zweifl., i, p. 199, 7. 

 f Chnjsops canifrons Walker, List, etc., I, p. 197. 

 9 . The hyaline triangle separating the crossband from the apical spot, almost readies the second longi- 



MEMOIKS BOST. SOC. XAT. UIST. YOL. II. 97 



