54 



Tachinid fly Cistogaster itntnaculata 55 



Pennsylvania Bumblebee Bombus pennsylvamcus 50, 52, 55, 176 



False Bumblebee Psithyrus variabilis 176 



Eucerid bee Melissodes bimacula 48 



Nomadid bee Epcolus concolor 48, 52 



Halictid bee Halictus obscurus 55 



Halictid bee Halictus fasciatus 48, 52 



Black Digger-wasp Chlorion atratum 55 



Pennsylvania Digger-wasp Chlorion pennsylvanicum 55 



Myzinid wasp Myzine sexcincta 52, 55 



Ant Formica pallid c-fuh'a schaufussi 



incerta 52 



The general conditions oi this prairie appear to have been less dis- 

 turbed than at Station I : at least the prairie vegetation is more exten- 

 sive and uniform. The change in the vegetation is apparently greater 

 than the change in the kinds of animals. Their feeding and breeding 

 relations appear to be much like those at the prairie stations previously 

 discussed. 



In the flowers of the cup-leaved rosin-weed fSilphiiim integri- 

 m) was found a giant bee-fly (Bxoprosopa fasciata) which had 

 been captured by the ambush spider (Misumena alcatoria), and on 

 webs in colonies oi this same plant the garden spider (Argiope auran- 

 was observed, with a grasshopper (Melanoplus differentialis) en- 

 tangled in the web. From the flowers of this SilpJr'um the following 

 - ::s were taken: Epicaitta marginata and E. pennsylvanica, Rliyn- 

 s aneus, Phymata fasciata, Encoptolophus sordidus, Melanoplus 

 tialis (nymph). Xiphidium strictum (adult and nymph). X. 

 luatum, Meli: bimaculata and obliqua. Epcolus concolor, and 



Halictus fasciatus. The margined blister-beetle f Epicaitta marginata) 

 - found both upon the flowers and the leaves of the plant. On the 

 flowers of the purple prairie clover {Petalostemum purpureum), Bom 

 cus, Xiphidium strictum. and Euschistus z-ariolarius 

 were taken. Collection 176 was taken from the flowers of Liatris 

 osa, and Xos. 55 and 178 from the flowers of Eryngium yucci- 

 foli: 



S\ .rms of the small corn syrphid. Mesogramma politum, were 

 present, on one day settling by dozens on my hands and clothes, where 

 they were easily grasped by the wing. It had been a warm day, and 

 this swarming was in the sunshine at about 4 130 p. m. The flies came 

 from a large corn field a few feet awav. 



