1863.] 
265 
dalis on joints 1—7 under and before the lateral setae, no traces of them 
being discoverable even in the living larva. 
The pupa, or at all events the $ pupa, has two robust obtuse abdomi¬ 
nal appendages, confluent towards their base and about two mill. long, 
and an inferior process of two similar ones which are connate through¬ 
out. The antennae are multiarticulate and longer than the head, and 
the tarsi are 5-jointed. In its general appearance it resembles the 
pupa of Sialis. 
Note 28, p. 182. Corydalis cornutus L. A most respectable 
man, who keeps the toll-bridge over Rock River where this insect is 
very abundant, informed me that on several occasions its larvae had 
fallen down one of his chimneys. His idea was that they must have 
bred there; but that of course is out of the question. The statement 
was confirmed by his wife and I have no doubt of its truth. In 1863 
I threw a larva of this insect into the Mississippi to examine into its 
customary mode of progressing in the water, which, as I found, was by 
crawling along the bottom not by swimming. As it emerged from the 
water, it climbed with ease up the stump of a large white elm, which 
was stripped of its bark and as smooth as any carpenter could have 
planed it. The stump was three feet high and upright, and when it 
had reached the top it commenced descending on the opposite side, 
but after a while lost its foothold and fell into the water again. The 
pair of 2-clawed appendages at the tail are used with much eflect to 
assist it in climbing. The building which it must have climbed to 
reach the chimney, down which it is stated to have fallen, was only a 
low one-story wooden one. I learnt from the same source that these 
larvae are nocturnal in their habits, for, though they are never seen 
travelling by day, they had several times been noticed running about 
in the dawn of the morning. Some which I bred to the imago state 
in 1861 never commenced travelling till after nightfall, and when 
thrown into a basin of water swam with vigor. They are much sought 
after as fish-bait, having a very tough integument so that one larva suf¬ 
fices to catch several fish, and are popularly known in the neighbor¬ 
hood of Rock Island as “^crawlers.’’ The larva, after it has left the 
water, retires under a stone or log or plank to hide during the day, and 
finally to change to the pupa state, and forms there an irregular cell in 
the earth. The pupa of the 9 ? oi' what I take to be that of the 9 , 
