251 



Psilocephala hmnorrhoidalis Macq. H.2, 4; Je. 6, Au. 18. (2) 

 Resting on bare sand. 111. 



Laphystia 6-fasciata Say. H.2, 4; Je. 6, 7. (2) On the bottoms 

 of deep blowouts in company with Microhembex monodonta, 

 which it somewhat resembles, especially when in action. No 

 other Illinois records. Common at the seashore. (Note 17) 



Dasyllis grossa Fabr. H.4, July 1. No other Illinois record. 



Proctacanthus brevipennis Wied. H.l, 2, 4; Je. 6, 7, 8, 23. (6) 

 Flying about vegetation in sandy places, and alighting on or 

 near the ground. No other Illinois records. These "robber- 

 flies" prey on other insects. 



Proctacanthus milbertii Macq. H.2, 3, 4; Au. 15, 18, 19, 20. (9) 

 With the preceding species; said to prey upon honey-bees 

 and grasshoppers. Sand ridges near L. Michigan, Wankegan. 

 Asilus agrion Jaennicke, a doubtful synonym, is the only 

 other record for Illinois. 



Erax mstuans Linn. H.l, 4; Je. 6, 7. (8) Common along sandy 

 roads near the Devil's Neck. La Salle Co., Mt. Carmel, Ur- 

 bana, sand at Waukegan ; Au. 16, 28, S. 25. 



Promachus vertebratus Say. H.l, Au. 22. 111. A common robber-fly. 



Asilus angustifrons Will. (Coquillett, det.). H.6, Je. 9. No 

 other Illinois record. 



Rhadiurgus leucopogon Will. (Coquillett, det.). H.2, 3; Au. 12, 

 17, 18. (8) This robber-fly is common at Devil's Hole. No 

 other Illinois records. 



Mesogramma politus Say. H.2, Au. 19. 111. 



Mesogramma marginata Say. H.2, Au. 19. 111. 



Volucella faseiata Macq. H.l, 2, 3, 4; Je. 6, 8, 23, Au. 12, 13, 14, 

 17, 18, 19. (14) This odd little syrphid is one of the charac- 

 teristic blow-sand species. The larvae breed in the tissues of 

 the cactus ( Opuntia humifusa) which grows abundantly in 

 this region (Smith, '91, Williston, '91). The adults are often 

 seen flying about, and abound on roadside flowers, such as 

 Verbena, dandelion, sweet clover, etc. No other Illinois 

 records. 



Conops sylvosus Will. H.3, Au. 14. No other Illinois record. 



Conops xanthopareus Will. H.l, 2, 4; Je. 6, 7, Au. 18. (4) 111. 



Zodion oblique fasciatum Macq. (leucostoma Will.). H.2, 6, Fekin ; 

 Au. 12, 18. (3) Urbana and Sandwich ; July 25 and 28. 

 Carlinville (Rob.). 



