No. 3-] HYGROCELEUTHUS AND DOLICHOPUS. 125 



We have examined types of all the species except latipes, 

 plumipcs, crenatus, afflictus, and ciliatus. The specimens 

 studied in the preparation of this paper are in the collection 

 of Dr. Wm. M. Wheeler, who kindly placed his collection at 

 our disposal. 



Although the name ciliatus has been previously used by 

 Walker, 1 Aldrich's ciliatus may remain, as Walker's species is 

 too poorly characterized to admit of its recognition. 



Males. 



Middle tarsi ornamented ......... 2 



Middle tarsi plain .......... 5 



2. Antennae largely black ..... Aldrichii Wheeler 

 First joint of antennae yellow . . . . . . . 3 



3. Middle tarsi strongly compressed . .... latipes Loew 

 Middle tarsi not compressed, first joint feathered laterally . . 4 



4. Middle tibia twice length of femur . . . Wheelerii, sp. nov. 

 Middle tibia not elongated, slender .... plumipes Scop. 



5. Cilia of tegulae yellow ......... 6 



Cilia of tegulae mostly black ....... 8 



6. Second abdominal segment laterally with a tuft of yellow hairs 



afflict 'us O. S. 

 Abdomen without such tuft . . . . . . . 7 



7. Face yellowish white ....... crenatus O. S. 



Face silvery ....... idahoensis Aldrich 



8. Arista bare ' ciliatus Aldrich 



Arista densely pubescent . . . . . . . . 9 



9. Front coxae yellow, postocular cilia in part yellow 



consanguineus Wheeler 

 Coxae black, postocular cilia wholly black . . var. propinquus 



Females. 



First joint of antennae yellow ........ 2 



First joint of antennae in great part black . . . . -4 



2. Species about 6 mm. first joint of middle tarsus yellow at base . 3 

 Species about 4 mm. Middle tarsi wholly black . . plumipes Scop. 



3. Hind tibiae wholly yellow, vertex green . . . latipes Loew 

 Hind tibiae black at tip, vertex violet . . . latipes var. cognatus 



4. Tip of hind tibiae black, or, if yellow, the wings narrow . 5 

 Hind tibiae wholly yellow ..... 6 



1 List of Diptera in Collection of British Museum, pt. iii, p. 661. 



