OF WASHINGTON. 139 



cylindrical, red, with the tip black. I was at first much in 

 clined to regard this as a synonym offormosa Wied. I have 

 noticed that the broad-bodied $ $ , when fresh and first cap 

 tured, have the abdomen of a very distinct red as well as 

 purplish hue, which settles into a dull purplish black as the 

 specimen becomes older. The reddish bases of the femora 

 vary much also, in some of my specimens being just percepti 

 ble, while in others the whole basal half is red. In one speci 

 men the palpi are darker than in the others. My specimens 

 offormosa have the palpi reddish or nearly black ; all but one 

 have the bases of the femora perceptibly red, while some of 

 the males have the abdomen purplish, and it nearly always 

 becomes purplish-black after drying for some time. There 

 fore, the distinguishing characters which Loew pointed out 

 between his species andformosa are not constant enough to be 

 of much service. The two species are, however, both valid, 

 and are easily distinguished, when a series of each is com 

 pared, by the wider abdomen in the $ , and the wider head 

 and thorax and general greater robustness in both sexes of 

 radiata. T. formosa uniformly has a narrower head and body, 

 and is less robust. There are no constant and well-marked 

 colorational differences between the two, but formosa as a rule 

 has darker palpi, less red on the femora, and less purplish on 

 the abdomen of the $ . 



T. trifasciata H. Lw. I have a $ of this species from Kansas. 

 It agrees well with Lcew's description, though the anal seg 

 ment, as well as the three preceding, has a golden or brassy 

 fascia, which is less interrupted in the middle than the others. 



T. haitensis Rob. Desv. The 9 is described. Mr. V. v. 

 Roder (Dipt. Insel Portorico, Stett. Knt. Zeit, 1885, 344) 

 makes this a synonym of pyrrhogaster. The latter seems to 

 be somewhat larger than haitensis, and they are both evidently 

 the same sex. I feel safe, however, in accepting Mr. v. 

 Roder' s synonymy as correct. 



T. mexicana Macq. I have not seen the description of this 

 species. 



T. nigricauda Bigot. I believe this to be the 9 . 



T.flavav. Roder, 1. c., 343, 344. Porto Rico. This is a 

 remarkable and exceptional species in its coloration, as it is 

 almost entirely yellow, including the wings. From the fact 

 that the face is golden, and from the general showy coloration, 

 it is probably the $ that is described. The 9 is always the 

 more sombre of the two. 



T. histris Walker, List. IV, 697, without locality. I have 

 little doubt that this is T. trifasciata H. Lw. The description 

 agrees in every particular, except that Walker's specimen 



