64 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



in large numbers is not uncommon, but during 1911 the 

 numbers were far in excess of those usually seen. In Dallas, 

 Texas, the swarms were so dense that some of the arc lights 

 were extinguished and great inconvenience was caused in 

 shops and homes on account of the ingress of the insects. 

 Its small size allowed it to pass through the meshes of such 

 screens as are used to keep out mosquitoes and house flies. 

 To say that it was found in millions upon millions around 

 lights both within and without buildings gives but an in- 

 adequate idea of the incalculable numbers that were present. 

 The invasion resulted in the closing of many shops as soon 

 as darkness began. This began on September 18 and contin- 

 ued until the 25th. After the latter date the numbers dropped 

 off very rapidly. 



This species occurred in great numbers in many places 

 outside of Texas. Prof. F. M. Webster informs the writer 

 that swarms similar to those which occurred at Dallas were 

 observed at Wellington, Kansas. At that place they appeared 

 first on September 20. 



Along with the specimens of Athysanus cxHiosns were 

 numerous other Hemiptera which Mr. 0. Heidemann has 

 determined as indicated below. It will be noted that a con- 

 siderable number of predatory forms occurred. 



Drcecucephala reticulata Ball. Mecidea longula Stal. 



Xerophlea viridis Ball. Reuteroscopus ornatus Rent. 



Pamera bilobata Say. Lygus approximates Reut. 



Julisus inultispinosus Ashm. Pceciloscytus basalis Reut. 

 Harmostes reflexiilus Stal. 



This swarming attracted all the more attention by reason 

 of the fact that it was simultaneous with the swarming of 

 Calosoma lugubre and Alabama argillacea. In fact, there 

 was such a conglomeration of species in such unsurpassed 

 numbers of individuals that the incident will long be con- 

 sidered historic by the residents of Texas. 



Records of the observation of enormous numbers of May 

 flies are not uncommon in the literature. The only special 

 interest of the present note is on account of the southern 

 locality. Apparently the great flights which have been ob- 

 served have taken place in much more northern localities, 

 as along the St. Lawrence River and the Great Lakes. In 

 May Mr. J. D. Mitchell observed remarkable multitudes of 

 Hexagenia biUneata Say on the Guadalupe River below Vic- 

 toria. This locality is at least a hundred miles south of the 

 latitude of New Orleans. The occurrence is well described 

 in Mr. Mitchell's notes, which read as follows : 



