282 E. T. CRESSON, JR. 



51. Legs entirely yellow. Mexican species 52. 



Femora in part black 53. 



52. Abdomen shining black, more or less cinereous laterally, antennas 



long acuminate 41. willistouii Kert. 



Abdomen opake, brownish, densly cinereous laterally; antennae 

 acute 40. flavicornis Will. 



53. Tibiae mostly yellow ; abdomen elongate, subcylindrical, shining. 



37. flavoniaculatus Hough. 

 Tibiae mostly yellow; abdomen short, robust, subopake and more 



or less fasciated 36. albofasciatus Hough. 



Tibiae mosty black {subvirescens group) 54. 



54. Abdomen subopake, or more or less submetallic, cinereous tinged. 



Western species 45. subiiiteiis n. sp. 



Abdomen shining, or at most only ventral margins cinereous... 55. 



55. Uppermost part of front shining or polished, only silvery near 



antennae 56. 



Front, except vertex, silvery or cinereous 48. albiseta n. sp. 



56. Post-trochanters and all femora with two or three long, distinct, 



bristles near bases beneath (Fig. 128). Western species. 



49. proximus n. sp. 



Post-trochanters with, at most, very short hairs or bristles ; ab- 

 domen ovate, with segments somewhat constricted at in- 

 cisures 43. similis Hough. 



Post-trochenters with minute scopa ; abdomen slender, not con- 

 stricted at incisures (Fig. 131) 46. scoparius n. sp. 



Post-trochanters unarmed ; abdomen normal 57. 



57. Abdomen polished all over 51. appeiitlipes n. sp. 



Abdomen cinereous on ventral margins and more or less apically. 



47. insiilaris n. sp. 



DESCRIPTIONS OF SPECIES. 



Group I. 



Stigma colored; abdomen opake, or subopake ; third section 



of fourth vein generally about twice as long as fourth. 



1. P. loewii Kertesz, fasciatus\\ Loew. 



d 1 . Opake-black ; antennae black; third joint short and obtuse. 

 Mesonotum opake, brownish-gray. Bases of abdominal segments 

 opake, black ; apex of first densely white ; apices of following gray- 

 ish, becoming whiter, thinner and less opake laterally. Hypopygium 

 moderate, black, not cleft. Legs black, apices of femora, bases of 

 tibiae yellowish. Wings grayish ; the colored stigma shorter than fourth 

 section. Length, 3.5 mm. ; wings, 4.1 mm. 



Described from Texas. I do not know this species, but 



