OF THE TABANID^E OF THE UNITED STATES. 389 



Althoiigli I have not received specimens of both sexes from the same locality, I hardly 

 doubt that the above described male really belongs to the female described as C mcechus. 

 The coloring of the body is very different in appearance, but the whole difference consists 

 in the degree of melanism ; while the characteristic traits in the coloration of the wings 

 are the same in both sexes. 



18. Chrysops morosus n. sp. 



? Chri/sops trinotatus Mncquart, Dipt. Exot., i, 1, p. IGl, 9. 



? . Tlie hyaline triangle separating the crossbaiid from tlic apical spot is narrow, acutangnlar, almost 

 crcsccnt-shaped, and readies the second longitudinal vein only; first basal cell infnscated ; abdomen hrown, 

 with three somewhat faint brownish-yellow longitndinal stripes; the intermediate one very narrow, the lateral 

 ones often abbreviated posteriori}'. 



Length, 7.5 mm. 



5 . Like the female, except the sexual characters. 



Female. Face ferruginous ; its lateral callosities brownish or black ; cheeks also brown- 

 ish or black, separated from the face by the usual ftdvous pollen ; palpi more or less brown- 

 ish. Autennre more or less reddish-yellow on the first two joints, blackish brown on the 

 third. Frontal callosity and a small area surrounding the ocelli, black. Thorax with the 

 usual greenish-gray median stripe ; lateral strijies yellowish (in some of the specimens they 

 do not exist) ; pleura3 with two 3'ellow stripes, separated by a brown one. Abdomen brown, 

 with three brownish-yellow, often almost obsolete, longitudinal stripes ; in one of my speci- 

 mens the stripes reach from the base of the abdomen to the fourth segment ; in other spec- 

 imens, the lateral stripes, which are broader than the median one, do not reach bejond the 

 hind margin of the second segment ; sometimes the lateral stripes are Ijarely visible as indis- 

 tinct yellowish spots. Venter brown, with more or less yellow on the sides of the first two 

 segments. Prevailing color of the legs reddish-yellow; distal half of the front tibiae and 

 the whole front tarsi, tips of the other tarsi, base of the femora, especially of the hind pair, 

 and end of the hind tibiae, black. Wings : root, costal cells and first basal cell, brown ; the 

 crossband is limited posteriorly by the intercalary vein, and completely fills out the fourth 

 posterior cell ; on the distal side the crossband is limited by a curve running from the sec- 

 ond longitudinal vein, almost opposite the end of the stigma, to the tip of the vein sepa- 

 I'ating the third and fourth posterior cells ; this curve forms the proximal side of the hya- 

 line crescent, separating the crossband from the apical spot ; the distal side of the crescent, 

 that is, the limit of the apical spot, is less definite, but may be described as running from 

 the same place on the second vein, across the tip of the second submarginal cell toward 

 the posterior margin. Thus the brown color fills out the marginal cell, except a small, but 

 very constant, hyaline dot at the end of the stigma ; it fills out the first submarginal cell, 

 except a triangular hyaline space, which is the apex of the crescent; it fills out the second 

 submarginal cell, except its proximal end (the base of the fork of the third vein) ; the first 

 posterior cell, beyond the crossband, is partly filled by the very much faded end of the api- 

 cal spot, partly hyaline, (in one of the specimens the brownish tinge almost reaches the 

 crossband). Second basal and anal cells, and the anal angle, hyaline ; a hardly visible 

 shadow on the last section of the fifth longitudinal vein sometimes communicates across 

 the fifth posterior cell with the crossband. 



MEMOIRS BOST. SOC. NAT. HIST. VOL. n. 



