270 The American Naturalist. [April, 
nel than tin, is easily broken, and I have not been able to see 
that it is, in practice, superior to tin. Although the action of 
the trap seems simple enough it may not be amiss to add a few 
words on this point. The insects that cluster about the elec- 
tric lights will dash against the vertical plate, c, and being un- 
able to obtain a foot-hold easily either upon its surface or that 
of the funnel, they will be likely to find their way into the in- 
side of the trap, where they are pretty certain to remain, be- 
ing prevented from escaping by the deadly fumes of the potas- 
sium cyanide and Irhe cone, c, whose polished lower surface 
lighted up by the holes mentioned above will attract them 
away from the single opening, 
• The disk, i, merely serves to keep a portion of the insects 
separate from the others while they are engaged in their des- 
perate death struggles ; it may, however, be farther utilized as 
a support for a coarse wire screen, which is not represented in 
the drawing. This screen will serve a useful purpose in allow- 
ng beetles and other small insects to escape through it to the 
bottom of the trap ; in this way only can moths be preserved 
n a fit state for museum specimens. The tube, ^, can be raised 
)r lowered so as to more or less completely close the opening 
n the bottom of the funnel and thus shut out all insects larger 
a certain size. My limited experience last summer with 
trap convinced me that it was of little use for collecting 
Lepidoptera, as they were usually ruined by the Coleoptera, 
which are much less easily overcome by the poison used. I 
have not tried the wire screen mentioned above, however, and 
this modification may preserve a considerable number very 
well. It answers the desired end very well indeed, however, 
for all the other orders, and it is especially useful in collecting 
small Hemiptera, Neuroptera, Diptera and Hymenoptera. I 
have frequently found a pint or more of insects in the trap 
when I came to examine it in the morning after exposure for 
a whole night. 
Many of the forms will of course occur in unwelcome abun- 
dance, and the task of looking over the whole mass carefully 
is no slight one but it pays. I have in a single night taken a 
few more than a hundred species, and in three consecutive 
nights as many as a hundred and fifty species, but I have no 
doubt but that this record can be easily broken if some of my 
experiment-loving brother or sister entomologists will follow 
the suggestions offered in this paper. — Jerome McNeill. 
