The filarial worms for which man is a normal host are not indigenous to the United States. Numerous other species of this family, however, are common parasites in fur-bearing animals of this country. Dogs, notably in this area and elsewhere in the coastal and Gulf States, are commonly infected with a heartworm, Dirofilaria immitis. This is an adult filarial worm which matures in the right heart and adjoining blood vessels. It is not to be confused with the very common intestinal parasites of the cat and dog, Ancylostoma braziliense and Ancylostoma caninum, and their larval stages, which produce the lesions of creeping eruption on the skin, so common to this area during wet periods. A survey of the literature reveals a total of 37 cases of human infection with spurious filarial parasites of lower animals which have been recorded. Of the three cases reported in the