182 THE AMERICAN NATURALIST. [VoL. XXXVI. 
Nothing appears to have been written of the species since 
Loew penned the original description. In fact, the immature 
stages seem not to have been described or figured for any 
American species of the family Bibionida. Mr. D. W. Coquil- 
lett, who determined my imagoes for me, having assured me 
that under the existing circumstances even a slight contribution 
to the knowledge of thesé things would be welcomed by dipter- 
ologists, T offer heréwith some observations on the habits of 
this species and a description of its immature stages. 
Habits. — My acquaintance with the habits of the species 
began as indicated above. On May 5 I collected a large num- 
ber of grown larvz and a few pupz about different stumps and 
placed them, with a quantity of their native soil, in a breeding 
cage. Imagoes began to appear on the 13th and continued 
transforming until the 20th. On the 18th, when my cage was 
full of fresh imagoes, I went out to the pasture but could find 
none there. In the earth were plenty of pupæ, but no more 
larvae. Perhaps the development of those in my cage was 
hastened by the higher temperature of the laboratory in which 
they were kept. About May 22 the first few imagoes were 
observed at large. On the 24th I discovered, on walking across 
the pasture, that the grass was full of them. A score could be 
swept up at each stroke of the net; but none were flying, for 
the air was chill. On the 26th, 28th, and 3oth, visiting the 
pasture again I saw the great swarms of them which I now 
come to describe. 
I was not prepared for any exhibition of aérial activity by 
what I had seen in my breeding cage. There the imagoes 
seemed hardly able to walk, to say nothing of flying. They 
were very sluggish ; they climbed the sides of the cage weakly, 
and tumbled about even in walking, and were handled without 
any thought of their getting away. Even in the field on the 
24th I had picked them up with my fingers and examined them’ 
 unconfined under a lens. But on these three later days warm 
sunshine had stirred them to unexpected activity. They were 
: flying i in countless numbers in the more sheltered places in 
the woods and were actively climbing about in the branches 
of Ene ecu MM an aces in pairs on the 
