ADAMS : NORTH AMERICAN DIPTERA. 435 



XYLOPHAGUS. 



TABLE TO THE SPECIES, 



1. First joint of the antenrife much elongated lovgicornis Loew. 



First joint of antecnte of usual length 2 



2. Legs in large part black lugeris Loew. 



Legs in large part luteous 3 



3. A yellow spot on each side near base of antennte reflectus Walk. 



Destitute of such spot ;^. . . 4 



4. Front entirely covered with grayish pollen 6 



Pollen of front reaching half-way, or more, from ocelli to antennae 5 



Front shining, a narrow band of pollen near ocelli riifi2)es Loew. 



5. Second, third, fourth and fifth segments of abdomen rufous, lateral mar- 



gins black abdorninalis Loew. 



Abdomen blackish throughout, shining deeorus Will, 



6. Tuft of white hairs on each side near base of antennae fasciatus Walk. 



Destitute of such hairs 7 



7. Thorax dorsum univittate (polished black line) triangularis Say. 



Thorax bivittate (pollinose stripes) gracilis Will. 



Thorax, except sides, pollinose throughout jjersequs Walk. 



Thorax shining throughout . nitidus, n. sp. 



Xylopliagus nitidus, n. sp. 



Female : Head black, occiput and cheeks shining, front and 

 face covered with grayish pollen, antenn;r dark, tip of second 

 joint yellowish, that of the third joint black, first joint a little 

 more than twice the length of second, third longer than the 

 first and second together ; proboscis yellow, palpi black ; 

 thorax shining, humeri, a narrow lateral Jine from humeri to 

 base of wings, postalar callosities, pile and halteres yellowish, 

 pleurae with a very few pile ; abdomen brownish black, shining, 

 pile yellowish ; coxse and bases of femora light yellow, apical 

 half of femore, four anterior tibise and tarsi brownish yellow, 

 posterior tibse, except each end, and their tarsi, dark brown ; 

 wings nearly hyaline, uniformly tinged with brown except on 

 cross-veins, where it is darker. Length, 10 mm. 



One specimen; Mt. Washington, New Hampshire. Geo. 

 Dimmock. 



