92 THE CANADIAN ENTOMOLOGIST. 



The next step comes in 1878, with the appearance of Osten Sacken's 

 second edition of his Catalogue of N. A. Diptera. In that he includes 

 Psilota flavidlpennis, Macq., giving the author's habitat, Philadelphia, and 

 calling attention to the note by Loew just referred to. It is very certain 

 that if he had found the species in nature, he would have mentioned the 

 fact. We must hence conclude that he had not, and included it simply 

 on the authority of Macquart, which makes it very uncertain that the 

 species is North American at all up to this date. 



Between this time and the time of the publication of Williston's 

 Synopsis it is evident that some specimens were captured in this country. 

 For Williston states that he found two specimens in the Loew type col- 

 lection which were labelled Psilota fiavidipennis at Cambridge. Hence, 

 it is certain from this time on that this species is a North American one, and 

 that Macquart's locality was probably correct, as was his determination. 



Now, Williston states that he has no doubt that these specimens so 

 labelled are buccaia, but that they zxo. flavidipemiis is doubtful. In other 

 words, he thinks that the correct determination of the specimens is as 

 buccata, and that Macquart's other species, Jlavidipeuuis, may or may not 

 be the same as that species. Hence, in his Synopsis he places Macquart's 

 description oi flavidipeniiis along with that oi buccata, as revised after an 

 examination of the specimens at Cambridge. 



Without assuming that my opinion will settle the matter at all, I may 

 say. that it seems that they are two distinct species. The colour of the 

 legs and of the abdomen is quite different. The two specimens from 

 Georgia that Williston mentions [Syn. App., 292] may and may not be 

 the true flavidipeniiis of Macquart. It is very doubtful. The less shin- 

 ing abdomen would seem to favor the conclusion that they are, while the 

 more concave face would point to an opposite conclusion. 



There are known in collections specimens of this species as follows : 

 In the Loew type collection, at Cambridge, two specimens ; in the U. S. 

 National Museum, eight specimens, six from Texas and two from Georgia ; 

 in Mr. C. W. Johnson's collection, at Philadelphia, several specimens 

 from Texas; and in the collection of the University here, one specimen 

 from Blanco County, Texas ; — this specimen has the pile everywhere 

 pure white. 

 Chilosia prima, n. sp. 



Female. — Eyes and arista bare (when magnified twenty diameters, 

 the arista shows distinct hairs). Face not pilose, scutellum without dis- 

 tinct marginal bristles ; legs almost entirely yellow. 



