NEW SPECIES OF HYGROCELEUTHUS AND 

 DOLICHOPUS, WITH REMARKS ON 

 HYGROCELEUTHUS.i 



AXEL LEONARD MELANDER and CHARLES THOMAS BRUES. 



The recognition of two new species of Hygroceleuthus and a 

 study of both sexes of the other American species of this genus, 

 and of another species which has been hitherto placed in Doll 

 cJiopics, have shown the necessity of revising this genus. Hith- 

 erto but little attention has been paid to the females, which are 

 very difficult to separate, whereas the males present very evi- 

 dent characters and are easily identified. 



Previous to 1868 only one species of Hygroceleuthus was 

 known from North America, and three others from the rest of 

 the world. Since then North America has produced at least 

 eight species, making it the richest country known in species 

 of this genus. 



Hygroceleuthus and Dolichopus are very closely allied, their 

 separation being effected by male characters alone. These two 

 genera form a group distinct from other Dolichopodidae by the 

 presence of a number of bristles on the upper surface of the 

 hind metatarsi. They have in common also the first joint of 

 the antennae hairy above, third joint short, its arista dorsal, 

 and hypopygium free. 



The so-called distinction between the two genera is to be 

 found in the length of the face which, in the typical males of 

 Hygroceleuthus, is lengthened and attains the lower corner of 

 the eye. Subordinate to this and even less constant are the 

 lengthened antennae, deep incision in the hind margin of the 

 wing, and broadened wings. In the three typical species of 

 Hygroceleuthus, which have tarsal ornamentation, this occurs on 

 the middle legs. In Dolichopus there is no species with the 



1 Cofttribiitions from the Zoological Laboratory of the University of Texas, under 

 the direction of W. M. Wheeler, 2V0. i. 



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