Pacific University Bulletin
For the past few years various agencies collecting fleas in south central Oregon have listed a small pale ground squirrel flea found there as Thrassis francisi C. Fox 1927. During 1939 the writer sent specimens of this species from Terrebonne, Oregon to Dr. Karl Jordan of the British Museum and asked for a verification of determination. Dr. Jordan replied that according to the original description the species was not typical and should be described as new.
The flea was determined to be Thrassis rockwoodi, a new species.
Hubbard, C.A. (1942). A New Thrassis (Flea) from California and Oregon and Fleas Carried by some of the West's Ground Squirrels. Pacific University Bulletin 38(6): 1-4.