134 MELANDER AND BRUES. [VOL. I. 



Moscow, Idaho. September. The original collection num- 

 bered about seventy-five specimens. 



LIST OF THE SPECIES OF THE GROUP HYGROCELEUTHUS. 



plumipes Scopoli, 1763. Ent. Cam., 334. 

 latipes Loew, 1861. Neue Beitraege, Fasc. viii., 5. 

 ? lamellicornis Thomson, 1868. Eugenies Resa, 511. 

 crenatus Osten Sacken, 1877. Western Diptera, 312. 

 afflictus Osten Sacken, 1877. Western Diptera, 313. 

 ciliatns Aldrich, 1893. Kan. Univ. Quart., 25. 

 idaliocnsis Aldrich, 1894. Kan. Univ. Quart., 154. 

 Aldricliii Wheeler, 1899. Proc. Cal. Acad. Sci., 3. 

 consanguineus Wheeler, 1899. Proc. Cal. Acad. Sci., 5. 

 Wheelerii Melander and Brues, sp. nov. 

 amnicola Melander and Brues, sp. nov. 



DolicJiopus. 



The following notes and descriptions were made from speci- 

 mens belonging to Dr. Wm. M. Wheeler, who has not only given 

 us his entire collection to work over, but has also tendered us 

 much aid and advice. 



The appended list is given in the hope that it may prove 

 useful, as it contains many new localities. It is interesting 

 to note that so many of Loew's species have been again 

 recognized. 



Dimorphism has not been noticed in the genus DolicJwpns 

 as yet, but a most interesting case of what may turn out to be 

 such is to be found in the species Hcns/iaivi and marginatus. 

 Of the more specific characters these two species possess in 

 common the following : antennae similarly colored, vertex vio- 

 let, fore coxae with dark hairs, hind tibiae with similar dark 

 glabrous stripes, similar wing neuration, and the yellow hind 

 femora of the male ciliated with black hairs, in which character 

 they differ from all other dolichopodes. On the other hand, 

 the males seem evidently distinct as follows : 



Hens/iazvi. Face generally yellow ; postocular cilia darker 

 yellow ; fore tibiae incrassated at tip ; fore tarsi ornamented 

 and banded ; hind tibiae not evidently darkened towards tip 



