376 C. R. OSTEN SACKEN'S PRODIiOME 



tendy to the liiiid border," the description of the four hind larsi, etc.) apply much better 

 to C. n'ujer. It must l)e Ijorne in mind at the same time that what Mr. Walker had as C. 

 nhjer is not Macquart's species at all, but my C. sordidus. 



Macquart's C. (iter, if we follow the letter of his description, may be the present species j 

 nevertheless his statements are too vague for a positive identification. 



5. Chrysops celer n. sp. 



?. Apex of the winiis liynline; proximal halt' of the two basal cells infuscateil ; body black; a conspicu- 

 ous tuft of yellawish-fernigiiioiis hairs on each side of the thorax. 

 Length, 11-1'2 mm. 



Female. Facial and frontal callosities as in C. excitans, only somewhat smaller ; the line 

 of fulvous pollen separating tlie facial callosities is broad and short ; on the front the pollen 

 is more grayish. Auteinia? ferruginous, except the latter portion of the third joint, which 

 is black. Thorax with a very ftxint grayish median stripe enclosed between two gray lines, 

 interrupted before the middle of the dorsum ; the latter is clothed with short, grayish-white 

 hairs. On each side of the thoraXj between the root of the wings and the head, there is a 

 conspicuous tuft of yellowish-ferruginous hairs, characteristic of the species. Abdomen uni- 

 formly black, clothed with a short, appressed grayish-white pubescence, which in well pre- 

 served specimens forms faint triangles in the middle of the second and third segments. Legs 

 black, the four posterior tarsi witli the first joint paler, except at tip ; the following joints 

 sometimes show a trace of the same pale color at the root. Wings : apex hyaline ; the cross- 

 band does not quite reach the posterior margin, but extends, although in a paler shade, into 

 the fifth posterior cell ; two basal cells filled out with brown up to the middle, or a little be- 

 yond ; anal angle and a portion of the anal cell tinged with gray ; the whitish halo along the 

 distal margin of the crossband is distinct. 



Hah. Not rare in the Middle States ; occurs also in Massachusetts. Eight females. 



In many respects C. celer is very like C. mitls, but is easily distinguished by the tufts of 

 ferruginous hairs on the thorax. The facial callosities of C. mitis are larger, the picture of 

 the wings usually not quite as dark, etc. ^ 



6. Chrysops sordidus n. sp. 



Ckrijaops niger Walker (nee Macquart), List, etc., I, p. "JOi. 



Q . Apex of the wings subhyaline; seeoml basal cell nearly hyaline, being infuscated at the proximal end 

 only; an ineijiieut apical spot in the shape of a faint cloud along the costa ; abdominal segments on the 

 posterior margins witii narrow gray borders, and with small gray triangles in the middle ; tirst and second 

 seo-meuts with small yellow spots on the sides. 

 Length, 9-10 mm. 



Fein'de. Frontal and facial callosities, and the yellowish-gray or grayish-yellow pohen 

 aromrd them the same as usual in this group. Antenna) lilack, first joint reddish, except 

 the tip (in some specimens the red is hardly perceptible). Thorax with a broad, Init faint, 

 grayish stripe, reaching beyond the middle and divided longitudinally l)y a faint blackish 

 line ; the lines which enclose it 9n the sides are Ijlackish (and not gray or yeHowish, as in C. 

 mitls, excitans, etc.). Thoracic dorsum clothed with yellowish-gray hairs ; tufts of longer 



