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Psyche 
[September 
quite common at Camp Pital and were present in consider- 
able numbers on the mule. It was noted that most of those 
on the animal at any one time were located about the head 
and neck. 
Tabanus calignosus Bellardi. This species was represented 
in our collections by only two specimens. One of these was 
taken inside the camp and the other was captured while 
feeding upon the mule. 
Tabanus festivus Hine. Five of these flies were collected 
at Camp Pital, three on July 13th and two on July 20th. 
They were not in evidence except while feeding, or about 
to feed, on the mule. They approached with a swift flight 
and after a short circling about darted at the animal and 
settled on the lower frontal area of its head. All five seemed 
to attempt to bite at almost the same spot. The first three 
captured were taken within an hour and although they came 
only one at a time the sites of the three bites could have been 
covered with a silver dollar. These flies were very wary and 
it was almost impossible to capture them until after they 
had begun to take blood. 
Tabanus fumomarginatus Hine. Five specimens were 
taken at Camp Pital, two in the camp on the evening of our 
arrival and three others later on the mule. 
Tabanus inanis Fabricius. Two flies of this species were 
collected by Dr. Clark as they were attacking the pack 
mules at Camp La Vaca in February, 1930. 
Tabanus leucaspis Wiedemann. Two of these flies were 
collected from the mule at Camp Pital. 
Tabanus occidentalis Linnaeus. This species was present 
in abundance and attacked the horses and mules at Progreso 
in August, 1931. Two specimens were collected by Dr. 
Clark at this time. 
Tabanus stenocephalus Hine. This species was quite 
common at Camp Pital and a number of specimens were 
captured as they fed upon the mule. They did not appear 
to favor any particular part of the animal. 
Tabanus unistriatus Hine. Many flies of this species were 
