OSTEN SAC KEN ON WESTERN DIPTERA. 287 



Ceraturgus. 



Ceraturgus lobicornis n. sp., $ ? . — The third antennal joint as 

 well as the first joint of the antennal style have the terminal lobes pro- 

 longed beyond the insertion of the following joint. Thorax black, beset 

 with short, appressed, golden-yellow pile. Abdomen yellowish-red ; 

 venter black. Legs reddish-yellow; base of front and middle femora 

 black. Length, male, 10-ll mm ; female, ll-12 mm . 



Face and front black, shining ; above the mouth a row of yellowish 

 bristles ; a few similar bristles on each side of the front, near the eyes. 

 Antennae black; third joint a little longer than the two first taken to- 

 gether; at the end, with two lobes, projecting beyond the insertion of 

 the next joint; the two following joints, forming the so-called antennal 

 style, taken together are somewhat shorter than the third joint; the 

 first of them is a little shorter than the second, and has two projecting 

 lobes, longer than those of the third joint. Thorax black, clothed on 

 the dorsum with moderately dense, short, appressed, golden-yellow hairs, 

 under which the shining black surface is visible ; in the middle, a gemi- 

 nate, nearly bare, black stripe, formed by lines of denser pile on its sides 

 and in the middle ; on the anterior part of the pleurae, a dense patch of 



I golden pile, followed by a shining black spot behind. Halteres yellow. 



I Abdomen yellowish-red above, smooth, shining; the extreme lateral 

 margins of the segments black (more distinctly so in the female) ; base 

 somewhat darker iu the male ; venter black. Legs reddish-yellow ; 

 coxae and trochanters black ; base of four anterior femora more or less 



I black; tarsal joints more or less brown at the tip ; the fifth, except the 

 root, altogether brown. Wings in the male tinged with brown, espe- 

 cially near the anterior margin ; the apex subhy aline ; in the female, the 



i basal half is yellowish, the posterior and distal portion brownish. (I 

 suspect that the coloring of the wings is very variable.) 



Rab. — Snake Eiver, Idaho (0. Thomas). Two males and one female. 

 I have a female from California (G. R. Crotch), the face and front of 

 which are brownish-red. The thorax also shows traces of reddish about 



] the humeri and on the pleurae ; the venter is red, and the four anterior 



I femora have no black at the base. I believe, nevertheless, that it is 



! the same species. The antennae of the specimen are broken. The speci- 

 mens from Idaho had been kept in alcohol ; hence the antennae are 

 somewhat distorted. 



Dioctria. 



Europe contains between twenty and twenty -five species of this genus 

 while in the North American fauna it was hitherto represented by two 

 rather aberrant species, D. albius Walker, from the Atlantic States, 

 and D. resplendens Loew, from California. A third species, D. pusio 

 n. sp., from California, is remarkably small, but nearer to the normal 

 type of the genus than the other two. 



1. Dioctria albius Walker, List, etc., ii, 301. — I have several spe- 



