T. D. A, COCKERELL. 67 



8. Fifth abdominal segment ( 9 ) black, contrasting with the rest, the middle 



being occupied by a triangular patch of black tomeutum, the sides 

 with inconspicuous light hair; flagellum red beneath ; size at least as 



large as maculifrons or albata.. flexi pes Cress. 



Fifth abdominal segment covered, at least over the greater part, with light 

 tomentum, and so not contrasting with the others 9. 



9. Females 10. 



Males 13. 



10. Apical triangle of hair on fifth abdominal segment black 11. 



Apical triangle of hair on fifth abdominal segment fulvous or brownish.. .12. 



11. Pubescence creamy-white; fifth abdominal segment with a .s?n«;? apical tri- 



angle of black pubescence ; flagellum red beneath ; face-marks cream- 

 color albata Cress. 



Face-marks decidedly yellow ; face broader (California). 



petrophila (Ckll). 



12. Pubescence oehraceous, quite fulvous on occiput; base of second abdominal 



segment broadly bare and black ; fifth with the apical triangle bright 

 fulvous; flagellum very dark reddish beneath; face-marks yellow, 

 the band on clypeus sending no streak upward in the middle line. 



maculifrons Cress. 



Pubescence white; imse of second abdominal segment covered with hair; 



fifth with the apical triangle light brownish ; flagellum bright red 



beneath ; band on clypeus sending a stripe upwards in the middle line, 



and face-marks very pale artliui'i Ckll. 



1.3. The two apical teeth of abdomen large, reddish, rounded at apex 14. 



The two apical teeth of abdomen reddish, but small and spine-like, not 

 greatly larger than the dark lateral teeth; pubescence white ; scape 



all black curta peritonize Ckll. 



14. Pubescence pale oehraceous, not fulvous on occiput; tarsi bright red, excei)t 

 perhaps basal joint of hind tarsi ; flagellum dark red beneath ; <;lyi)eal 

 yellow band as in 9' sending no streak upward; lateral basal teetli 

 of seventh abdominal segment small and dark. 



maculifrons Cress. 



Similar, but tarsi darker, and yellow reaching upper margin of clypeus in 



median line ; scape yellow in front flavocincta Huanl. 



Group E. (Series 1.) 



impedes of rather large or large size ; thorax above with conspicuous black, as well as 

 pale, hair ; abdominal bands, when present, due to hair. 



Mesothorax with pale ochreous hair, but all of thorax behind level of wings with 

 black hair; size larger than bomboides stanfordiana Ckll.'- 



••■'In A. solitaria Rits., the hair on inner side of basal joint of hind tarsi ( 9 ) '^ 

 splendid red-golden ; in stanfordiana this hair is dark. In Canad. Entom., IQOo, 

 pp. 313-314, Mr. Viereck erroneously credits solitaria to me, and in his table 

 makes it difi\;rent from insularis. It is, of course, the same as insularis, being 

 merely a substituted name. 



TKANS. AM. KNT. SOC. XXXII. JANUARY, 1906. 



