JOURNAL OF ENTOMOLOGY AND ZOOLOGV 17 



rnlly-nrowii ])11i>:t! traiisfoniUM] in tlie pail while heiny- broug-lit 

 into the laboratory. The krva> are almost ceiiainly carnivor- 

 ous, their powerful sickle-shaped luaiidihles inflictiiii;- a paiiitnl 

 bite on tender parts of the hand. 



The lai'\-a' of E. f iiUomiisis were i'onnd in the same situations 

 on ^fay .'!<). They occurred in company with numerous .spinosa 

 lar\;i' aud juipa!, a few large Tabanid larvffi, a small Tabanid 

 pupa, aud the following beetle associates: Bembidium, Schizo- 

 (ji iihis, 'J'dcliiiy, Cryptohinm bicolor, etc. These larv£E were placed 

 in breeding-.jars on May 30. One of these larva?, ]iupated on 

 June 1 and emerged as an adult on June 6. This gives a very 

 short indoor pupal period of a trifle less than a week. 



The habits of the adult flies are still not well known. At 

 5:00 p. jn. on May 1, 191.1, the swarming of the species was 

 observed near the ])lace described above. At 5:40 ]>. m. they 

 were flying in some numbers, swarms averaging from thirty to 

 forty individuals being the most common. They kept out in 

 the o]ien. away from trees or bushes, and inaintained an aver- 

 age licii^ht of from thirty to forty feet above the ground. Most 

 of the swarms were out above the creek-bed but others were 

 above the banks of the stream. The entire swarm seemed to 

 face the gentle easterly breeze (i. e., up-stream). They swarmed 

 about on a horizontal plane, the motions of each individual 

 being mostly like a ti.gure 8. The swarm covered considerable 

 space, being from eight to ten feet high and about one-half of 

 that distance through, the swarm scarcely moving from its 

 position. Individuals constantly leave and rejoin the swarms. 

 The insects sit on the toi)s of the willow bushes before joining 

 the swarms and at this time are very wary. They dart up into 

 the ail' aud far (ncrhead at the first approach of a jiossible 

 e-uemy. 11 is xcry haid to catch specimens from the groimd, 

 but by standing on the bridge, which is only a little lower than 

 the level of the swarm, it is rather easy to cajtture deitarting 

 and incoming individuals. The next night, May 2, at 5:30 p. m., 

 the insects were again swarming in numbers; at this time the 

 swarms were .sinaller, of from twenty-five to thii'ty individuals, 

 anil they swarmed (piite low, ten to fifteen feet u]), just out 



