58 INSECTS AFFECTING DOMESTIC ANIMALS. 
Simulium sp. 
Baron Osten Sacken, in his careful paper in the American Entomolo- 
gist on the habits and structure of species of Simulium, describes a 
larval form common in streams near Wash- 
ington, but does not connect it with any 
species described in the adult form. His fig- 
ures, which represent only certain parts of 
e 
4 the anatomy, are here reproduced (fig. 21). 
lil Hil : Possibly the observations made by Dr. 
| ly My Ne Howard may refer to the same species. In 
e i this case the larve are found attached to the 
FiG. 21.—Simuliwm sp.: a, portion rocks forming the bed of the stream, and 
of ray of fan; b, mandible; ¢ their habits generally conform with those of 
maxilla; d, under lip; e, upper y 
lip—all enlarged (after Osten the Northern species. 
Sacken). 
Simulium pictipes Hagen. 
This species has already been mentioned as described by Hagen 
(Proc. Bost. Soc. Nat. Hist., Jan., 1880). 
Larve and pup occurred in the Au Sable River, Adirondack 
Mountains. 
Family TABANID 4. 
(Horse Flies, Gad Flies, ete:) 
The members of this family are large, some of them being among the 
largest of the order Diptera, and the females are provided with pow- 
erful mouth parts by means of which they inflict very painful bites 
upon cattle, horses, and other animals. Man does not escape, and as 
they are able to penetrate even thin clothing worn in summer, they 
sometimes become a source of annoyance to workmen in fields. 
The bodies are never very hairy, the head is large and composed 
almost entirely of the eyes, which during life are of brilliant colors 
and varied reflections. The antenne are prominent and the third joint 
is composed of from three to eight minute rings, a character which, 
with the large eyes, distinguishes them at once from nearly all other 
large flies. The strong piercing mouth parts of the female are com- 
posed of six lancet-like organs, while in the male there are but four 
and these are not adapted to piercing the skin of animals. The males, 
and also the females, if not finding other food, feed upon the nectar of 
blossoms or the juices of plants, exuding sap from trees, etc. 
The flight of these flies is very strong and rapid and is attended with 
a buzzing, tormenting noise. The males may often be seen with the 
wings vibrating so rapidly that they become invisible, resting motion- 
less in one place and then darting rapidly and resting suddenly again, 
generally turning the head in some other direction each time they dart, 
