1878.] 61 ‘[Hagen. 
Once I found that freshly raised Bombycide were infested by them 
on the spreading board; now every spreading board is carefully 
cleaned, and the cracks washed with alcohol before it is used. After 
all I do not consider them dangerous in a well kept collection. 
A species of Acarus, probably Tyroglyphus, was only once im- 
ported with a box of insects. I knew them very well as one of the 
most dangerous enemies, and at once prevented their increase. Of 
all the insects mentioned, I consider only Attagenus megatoma and 
Anthrenus varius and scrophularie as really dangerous pests. Der- 
mestes lardarius cannot be at home in a well kept collection, and 
mostly appears by bad fortune, which sometimes happens in a large 
museum only. The entire separation of the entomological rooms 
from the rooms for the other animals, specially for mammals, birds 
and skeletons, can prevent their intrusion. This is always done in 
every large and well kept museum. 
It is rather interesting to compare the museum pests in Europe 
with these data, which of course apply only to the Museum of Com- 
parative Zoology, and I am not aware that other data about Ameri- 
can museum pests are published. 
D. lardarius is there as common as it is here, and too large to be 
easily overlooked, therefore not really dangerous. Aifagenus pellio 
and megatoma are both common in countries, but in Europe A, 
pellio is a real pest, and very troublesome; here A. megatoma is 
exceedingly dangerous, though I never heard of injury done by it in 
Europe. The species of Anthrenus show a similar distribution. 
A. museorum and A. varius are both common in Europe, but only 
the first is a very important pest; the latter I never saw in collec- 
tions, though it is here the most dangerous enemy. A. scrophula- 
rice, now very obnoxious here, is known as dangerous for woollen 
cloths and hides, or similar things, and is mentioned by Herbst in 
museums. 
Tribolium, a very cosmopolitan insect, is nowhere recorded as a 
pest except in imported East Indian collections; and probably also 
in Kast India. 
Concerning the moths I am not prepared for a definite statement. 
T. flavifrontella I do not find recorded as injurious in Europe, and 
I believe the moth destroying European collections is a different 
species, probably O. sarcitelia. But I had then no special knowledge 
of the moth, and therefore Iam not able to give a decided opinion. 
