344 NEW YORK STATB MUSEUM 
and our animals are repelling substances, such as stinking oils 
andsmudges. Anumber of repellents are sold, and some of them 
are very good, for instance the “Black-fly cream,” made in | 
Portland Me. Our fishermen and hunters frequently use a mix- 
ture of kerosene oil and mutton tallow, with which the exposed 
parts are greased. For animals any of the strong smelling oils 
can be used, but repeated applications are apt to hurt them or 
to remove the hair. Oil of tar is a simple and easily applied — 
wash. To make it, a quantity of coal tar is placed in a large 
shallow receptacle in which is stirred a small quantity of oil 
of tar, or oil of turpentine, or any similar material. After fill- 
ing the receptacle with water it is kept undisturbed for sey- 
eral days, when the animals to be protected. are washed with 
the impregnated water whenever necessary. Smudges are the 
best as a protection and the animals soon realize their pro- 
tection and crowd to them for shelter, even refusing to leave 
them when needed elsewhere. As the black flies are active 
during the day only, and the mosquitos towards evening and 
night, dwellers in our northern woods have a bad time of it 
and sometimes suffer very greatly on their account. It is easy, 
however, to drive these tormenters from houses or tents. By 
burning inside of them a little Pyrethrum powder (Persian or 
Dalmatian insect powder) upon a piece of bark these intruders 
are either killed or so stupefied that they do not bite for some 
time. This method is in general use in the houses and stores 
of the Hudson Bay Company, and the writer has always used - 
it successfully in his numerous trips. The fumes of the burn- 
ing insect powder are not very offensive, at least not nearly so 
much so as the poisonous bites of such insects as black ilies 
and mosquitos. Luggert 
Structural characters 
There is but one genus of the family Simuliidae, Simulium, 
which possesses the characters of the family. 
The eggs of the known species are deposited in a compact 
layer on the surface of rock over which water is flowing in sit- 
uations as shown on plate 32. Their shape is elongate ellipsoidal, 
but they are usually closely packed with the long axis vertical 
and hence assume a polyhedral cross section. Eggs of the dif- 
ferent species doubtless vary in size, those of the larger spe- 
cies (e. g. S. pictip’es) measuring .40 by 18mm. In 
1Minn, Agric. Exp. Sta. 1896. Bul. 48, p.207. 
