240 DIPTERA OF NORTH AMERICA. [PART II. 



treme tip of the male abdomen ; this species, which. I have called 

 P. caudatulus, differs, however, from P. caudatus by its smaller size 

 too much, to be mistaken for it. In Wiedemann-Winthem's collec- 

 tion no information whatever is to be found about P. caudatus. In 

 the Berlin Museum there is a specimen of P. comatus, under the 

 name of P. caudatus ; I cannot, however, acknowledge the correct- 

 ness of this determination, as Wiedemann distinctly says that the 

 female of his P. caudatus has no black femora, like the male, but 

 yellow ones, while this is not the case with P. comatus. The typical 

 specimen of P. caudatus is in Westermann's collection. 



11. virgo Wied. The description of a female, which also seems to belong 



to the circle of relationship of P. scobinator. The statements which 

 Wiedemann gives about it are so uncertain, that no conclusion as 

 to the species to which the described specimen belonged can be 

 drawn from them. The size, as stated by Wiedemann, is more con- 

 siderable than the size of the females of all the species of this rela- 

 tionship that are known to me. The typical specimen is not to be 

 found in Wiedemann's collection, so that a satisfactory solution as 

 to this species is probably never to be expected. 



12. mundus Wied. Of this species there are two males in Winthem's 



collection, marked as Wiedemann's types. Had I known them be- 

 fore I published the Eighth Part of the " Neue Beitrage," I should 

 not have ventured to describe in that volume P. ciliatus as a species 

 different from P. mundus. Certainly both specimens in Winthem's 

 collection are very much smaller than the male, which was the type 

 of my description of P. ciliatus, and their coloring is darker and 

 more distinctly violet ; but in all the plastic characters there is 

 much similitude between them and the male, which I have de- 

 scribed. The only plastic difference, which I can discover, is the 

 following : in P. mundus there is, besides the row of bristles on the 

 outside of the fore tibiae, also a second row, placed further towards 

 the inside, and which is tolerably complete ; in P, ciliatus this 

 second row is also present, but it is as complete as in P. mundus 

 only in the vicinity of the root of the tibiae, further on it is (appa- 

 rently) more incomplete; however, no accurate judgment can be 

 based on a single specimen, and moreover the difference is so trifling, 

 when compared to the great conformity in the extraordinary struc- 

 ture of the wings and of the fore tarsi, that too much stress is not 

 to be laid upon it. As the name " dllatus'' has already been be- 

 stowed upon this species, I may be permitted to retain it, until the 

 identity of the species, so named, with P. mundus has been more 

 positively established. A separate description of the latter is unne- 

 cessary, as no mistake can occur if a proper attention is paid to the 

 description of P. ciliatus, as well as to what has just been said 

 about these species. 



13. radians Macq. First described in the " Suites d, Buffon /" the same 



