376 C. R OSTEN SACKEN'S PRODROME 



tends to the hind border," the description of the four hind tarsi, etc.) apply much better 

 to C. nicjer. It must be borne in mind at the same time that what Mr. Walker had as C. 

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



Macquart's C ater, if we follow the letter of his description, may be the present species; 

 nevertheless his statements are too vague for a positive identification. 



5. Chi-ysops celer n. sp. 



$ . Apex of the wings hyaline ; proximal half of the two basal cells infuscated ; bodj' black ; a conspicu- 

 ous tuft of yellowish-ferruginous hairs on each side of the thorax. 

 Length, 11-12 mm. 



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

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

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

 is black. Thorax with a very foint 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 thorax, 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 with 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 Avhitish halo along the 

 distal margin of the crossband is distinct. 



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



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

 ferruginous hairs on the thorax. The facial callosities of C. 7nitis are larger, the picture of 

 the wings usually not quite as dark, etc. 



6. Chrysops sordidus n. sp. 



Chrysops niger Walker (noc Macqunrt), List, etc., I, \\ 202. 



$. A|)ex of the wings siibhyaliiie ; second basal cell nearly hyaline, being iufiiscated at the proximal end 

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

 posterior margins with narrow gray borders, ami with small gray triangles in the middle ; first and second 

 sefnieuts with small yellow spots on the sides. 



Length, 9-10 mm. 



Female. Frontal and facial callosities, and the yellowish-gray or grayish-yellow pollen 

 around them the same as usual in this group. Antennse black, first joint reddish, except 

 the tip (in some specimens the red is hardly perceptil^le). Thorax with a broad, but faint, 

 grayish stripe, reaching beyond the middle and divided longitudinally by a faint blackish 

 line ; the lines which enclose it on the sides are blackish (and not gray or yellowish, as in C. 

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



