AMERICAN DIPTERA. 275 



29. Hind femora infuscated along tlie entire tipper edge iFla. ). 



Paraclitis propinquiis Wlieeler. 

 Hind femora infuscated at the tip, or not at all 30. 



30. Face of female brown in the middle 31. 



Face of female not brown in middle 35. 



31. Fore coxae infuscated beyond the middle • 32. 



Fore coxiB not or scarcely in fuscated 33. 



32. Lamellae of hypopygium straight, with rounded tips (U. S., Mex.). 



Pelatittoiieurus vag3iii!« Loew. 

 Lamellse curved, with acute tips (Cal.). 



l*elaNl«>iieuiMis ocoideiitalis Wheeler. 



33. Arista of male long, with blunt tip (Wis.. 111., La.). 



I'elastoiieiirus neglectus Wheeler. 

 Arista of male as usual 34. 



34. Lamellae of hypopygium black (Fla.^. 



I'olaMtoiieurus floridaniis Wheeler. 

 Lamellae yellow, or mainly so (W. I.). 



Pela^foueurus laNcialir* Roeder. 



35. Antennas wholly black (W. I.) Paracliiis arciiatUN Loew. 



Antennae not wholly black 36. 



36. A double black spot before the root of the wing, of which the anterior part 



extends towards the middle of the dorsum (W. L). 



Parading quadriiiolatus AUlrich. 

 Ante-alar spot not divided 37. 



37. Thoracic dorsum with one or more distinct longitudinal lines 38. 



Thoracic dorsum without lines 39. 



38. Thorax dark bronze-green (N. Y.i. 



Pelastoiieiiriini alleriians Loew. 

 Thorax bright blue-green (W. I., Mex.) . .Sarcioiius lineatiis Aldrich. 



39. Upper part of the face bright green (W. I., Mex.). 



Pela$«toiit'urus argeiitifer Aldrich. 

 Upper part of the face white-dusted 40. 



40. Last section of fourth vein curved in the middle (W. I.;. 



Paraclius veiiiistus Aldrich. 

 Same curved distinctly beyond the middle (W. I.). 



Paraciiiis belliiiii Aldrich. 



In the table, the section nuniljered 19 and 20 presents the great- 

 est difficulty. I am unable to recognize abbreviatus in any of my 

 material, and it may be the same as longicauda, in which the spot 

 before the scutellum Is sometimes evanescent. There seem to be 

 some specimens of lamellaius in which the dorsum of the thorax is 

 not violet but dark bronze. They n)ay belong to a distinct species, 

 but I cannot settle the question with my material. In otiier re- 

 spects the table ought to work well after a little familiarity with it. 

 Leptocorypha pavo Aldrich, from St. Vincent, W. I., is a near rela- 



TRANS. AM. ENT. SOC. XXX. SEPTEMBER. 1904. 



