SYNOPSIS OF NORTH AMERICAN SYRPHID^. 19 



also, there is a black ring on the hind tibiae, and the hind metatarsi 

 also black ; often the black is wholly wanting, the legs are then yel- 

 lowish red with the tip of the femora and the base of the tibia; light 

 yellow. Wings, nearly hyaline ; stigma, dilutely yellow. 



Ten specimens from Montana (Professor Comstock) ; one from Gar- 

 land, Colo. (Professor Riley); one from Como, Wyo.; two from Wash- 

 ington Territory ; one from Southern California; and four from Connecti- 

 cut. The species is very variable. In Europe there has been much 

 confusion, as will be seen from the list of synonyms, which I have re- 

 produced from Schiner. To this author our knowledge of the variations 

 is chiefly due, and hence the following translation of his description 

 and remarks will be valuable : "Abdomen black ; in the middle in greater 

 or less extent, yellowish red. When the black is confined to the base 

 of the abdomen, the first segment, at least, is always black, or, in the 

 middle behind, there may be a small red spot, and the black color does 

 not here appear spotted. Ground color metallic black or dark bronze 

 green. Dorsum of thorax with two median stripes reaching nearly to 

 the middle, sometimes wholly wanting. Antenua3 brown. Abdomen, 

 except the base, wholly yellowish red (var. testaceus); or yellowish red 

 with the base and tip black, and on the third and fourth and fifth seg- 

 ments with white pilose arcuated spots (var. arcuatus and hicolor) ; or 

 with these pilose spots wanting (var. taeniatus); or the reddish color is 

 confined to tip (var. rujicauda), in which case the scutellum is wholly 

 black. The legs are yellow with the base of the femora black, some- 

 times with a black ring on the hind tibijie, and with darkened meta 

 tarsi. 



«"A careful examination of my rich material has given me no better 

 results than the above. It is difficult to believe that the long, slender 

 varieties, four millimeters in length, and the robust specimens, six milli- 

 meters in length, should belong to one and the same species, and yet 

 we find between these extremes, numerous connecting forms. The color 

 has no value, plastic differences are wholly wanting ; specimens occur 

 in which differences of neuration exist in the two wings of the same 

 individual.* 



"'Sijecimens have beeu taken in copula of P. hicolor and P. testaeeuSj 

 P. testaceus and P. tceniatusJ^ t 



Paragus tibialis. (Plate I, fig. 8.) 



Pipiza tibialis Fallen, Dipt. Suec. Syrph., 60, 5. 

 Paragus hwmorrhous Meigen, Syst. Beschr., iii, 182, 10. 

 . Paragus aueus Meigen, 1. c., 183, 11 ; Zetterstedt, Dipt. ScaM., ii, 854, 8. 

 Paragus ohscurus Meigen, 1. c, 183, VZ. 



Paragus tibialis Meigen, I.e., 183, 13; Zetterstedt, Dipt. Scand., ii, 852,6. 

 Paragus fern or atus Meigen, 1. c, 184, 14. 

 Paragus trianguUferus Zetterstedt, Dipt. Scand., ii, 853, 7. 

 Paragus sigiUafus Cnitis, Brit. Ent., .")93. 



* Fauna Austr. i, 259. t Verb. Z. B. Ges., vii, 301. 



