96 Psyche [June 
species of Nematode worm which had every appearance of being 
an internal parasite. 
Under the same date it was mailed to Division of Entomology, 
where it was duly received and given a division number 3498°. 
Doubtless the specimen has long ago disappeared, but it is this 
to which Mr. Malloch refers in his paper and may perhaps belong 
to the same species as was later found infesting larvee of Simulium 
in the Sangamon and Illinois Rivers, and which Mr. Strickland 
years after has been able to carefully study. 
On May 11, 1887, the writer while engaged in studying buffalo 
gnats and other species of Simulium in the St. Francis River at 
Madison, Ark., encountered a species of fly which were locally 
termed ‘“‘black gnats.” These acted very much like true buffalo 
gnats, although I was not able to observe them biting animals. 
Specimens were mailed to the Department of Agriculture and the 
notes of the Division of Entomology show that they were received 
May 14, 1887, and given the division number 4133. They were 
described as agreeing closely with the genus Hilara- but differing 
by having mouth organs longer than the head, and by possessing 
a stigma-like black spot near margin of wings. A year later, or 
to be exact, May 6, 1888, the writer was again in the same locality 
engaged in the further investigation of Simulium and again en- 
countered these flies in abundance. It would seem that, as they 
belong to a group known to be predaceous, they were presumably 
attacking the gnats, although I do not find that this was actually 
observed by me. 
While camping on Devil’s River, about fifty miles from the 
point where it empties in the Rio Grande, March 20 to 25, 1891, 
larvee, pup and adults of a species of Simulium not recognizable 
as belonging to either S. pecuarum or S. meridionale were found 
in abundance. Specimens of all stages were forwarded to Wash- 
ington where they appear to have been received May 9, and given 
the division number 5003. One of these adults, captured while 
in the act of attacking a horse, was infested by larve of a water 
mite, division number 5003°. This is the larva of a Hydrachnid 
agreeing with Limnesia. 
A precisely similar observation was made by myself July 30, 
1884, at Oxford, Ind., where an adult mosquito was discovered 
with one of the water mites attached thereto. 
