♦AMERICAN DIPTERA. 275 



29. Hind femora infuscateii along tlie entire upper edge rFla.). 



Paraclitis propinquiis Wheeler. 

 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 coxse infuscated beyond the middle 32. 



Fore coxa; not or scarcely infuscated. . . 33. 



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



Pelastoneurus vagaus Loew. 

 Lamellae curved, with acute tips (Cal.). 



l*eIa!«toiieiiriis occidentalism Wheeler. 



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



Pelastoiieiiriis neglcctuK Wheeler. 

 Arista of male as usual 34. 



34. Lamellae of hypopygium black {Fia.K 



Pelastoneuriis floridaniis Wheeler. 

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



Pela<>toneurus fascial U!h Roeder. 



35. Antennae wholly black (W. I.) Parading arciiatn»i 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). 



Paracliiis quadriiiotatiis Aldrich. 



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. 



Pelastoiieiiriiin alteriians Loew. 

 Thorax bright blue-green (W. L, Mex.) . .Sarcioiius lineatus Aldricb. 



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



Pela!«toiieurus argeiitifer Aldrich. 

 Upjier part of the face white-dusted 40. 



40. Last section of fointh vein curved in the middle (W. L). 



Paracliiis veniistus Aldrich. 

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



Paracliiis beliiis Aldnch. 



In the table, the section numbered 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 lamelhdus in which the dorsum of the thorax is 

 not violet but dark bronze. They may belong to a distinct species, 

 but I cannot settle the question with my material. In other 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. 



