In October, 1934, several specimens of a tick belonging to the genus Ornithodoros were forwarded to the Bureau of Animal Industry for identification by Drs William Thompson and N. E. Dutro. These ticks were first observed by Mr F. E. Swan of the Bureau of Entomology and Plant Quarantine in a carload of bat guano originating at Linares, Mexico, and held in quarantine at Matamoros, Mexico.