1896.] NATURAL SCIENCES OF PHILADELPHIA. 51 



70. Abdomen dark Avith light bands 48 bigelovice 9 



Abdomen light with dark bands 71 



71. Mesothorax very shiny, dark blue-green ... 47 nitidella 9 

 Mesothorax dull, hairy, brassy-green 28 snowii 9 



72. Dog-ear marks absent 73 



Dog-ear marks present, or at least represented by dots . . 88 



73. Abdomen with the last two segments bright rufous, the 



others white with black bands 19 crotonis 9 



Not so 74 



74. Bands of abdomen at least mostly entire 75 



Bands of abdomen all interrupted 80 



Abdomen dark without bands 82 



75. Stigma solid dark brown or black, clypeus with two broad 



black bars, lateral pale areas of face pinkish, 39 numerata 9 

 Stigma hyaline, at least centrally 7t> 



76. Anterior legs entirely yellow, mesothorax dull, sides of face 



broadly yellow up to level of antennoe, then for a short 



way suddenly very narrowly 27 rectangulata 9 



Anterior legs partly black 77 



77. The black bands of abdomen not united on lateral margin, 



anterior tibiae all yellow, lateral pale triangle of face 

 coming to a point above, face-markings lemon-yellow . . 



8 zonalis 9 

 The black bands of abdomen more or less united on lateral 

 margin, anterior tibire with a black mark behind .... 78 



78. Lateral triangle of face obliquely truncate above ; a bluer 



species 48 bigelovice. 9 var. 



Lateral triangle of face coming to a point above, but nar- 

 rower than in zonalis, face-markings pallid ; a greener spe- 

 cies 79 



79. Supraclypeal mark broad, notched in middle . 24 bakerce 9 

 Supraclypeal mark narrower, or reduced to two spots . . 



23 zebrata 9 



80. Female, flagellum only pale testaceous beneath 



25 affinis 9 var. 

 Males 81 



81. Flagellum dark; species of eastern U. S. . 11 odomaculata. 

 Flagellum mostly yellow ; species of Lower California . . . 



67 sparsa. 



82. Head large, quadrate, face very hairy .... 62 latlceps $ 



