64 The Ohio Naturalist. [Vol. IV, No. 3, 



tried for procuring a supply of fine specimens of the small Diptera 

 common in marshes. 



The best of results in collecting Ephydrids may be obtained by 

 sweeping grasses in low ground in the vicinity of water, or along 

 the margin of streams, but specimens procured in this waj^ are 

 apt to be teneral and not so desirable as those taken from flowers. 



DiCHAKTA Meigen. 



There are three descriped North American species in this 

 genus. Two of them, caudata and brevicauda, are distinguished 

 from species of Notiphila by the uniform dark color of the body, 

 but not so with furcata which has the abdomen distinctl}- bicol- 

 ored. The males of all the species are characterized by the 

 elongated bristles at the tip of the abdomen. The following key 

 is offered for separating the species of the genus : 



1. Abdomen uniformly dark, nearly black in color 2. 

 Abdomen bicolorous furcata Coq. 



2. Last segment of male abdomen distinctly prolonged 



into a conical point caiidala Fallen. 



Last segment of male abdomen not noticeably pro- 

 longed brevicauda Loew. 



Notiphila Fallen. 



This genus is represented in Ohio by a number of species. N. 

 unicolor L,oew is probably the most abundant .species of insect 

 to be found at Sandusky during a part of the summer. The eggs 

 of this species are deposited on various leaves over the water, and 

 so abundant are they at times that large areas of wild rice and 

 other plants are colored white by them. Oviposition seems to 

 take place mostly in the evening and in egg-laying season the 

 flies collect on the plants by thousands, so that one in a row-boat 

 at du.sk may .see water plants almost entirely covered by them. 

 The adults are most abundant in July. When the eggs hatch the 

 larvae drop into the water and sink to the bottom. 



Psilopa fulvipennis n. sp. 



Shining black or violaceous. Antennea red, except the- third .segment, 

 which is partially fuscvis, thorax and abdomen deep shining black with a 

 violaceous tinge, legs black with the exception of the knees, apexes of the 

 tibiae, and the tarsi, which are red. Wings uniformly brownish yellow all 

 over, knob of halteres yellow. Length slightly under 2.5 millimeters. 



Habitat: Three .specimens procured at Cameron, Louisiana, 

 August 20. Taken by sweeping from grasses growing in low 

 ground. 



The uniform brownish 3'ellow wings, together with the shining 

 black thorax and abdomen characterize this species. 



