THE ZOOLOGICAL CHARACTERS OF THE ROUNDWORM GENUS FILARIA 
MUELLER, 1787, WITH A LIST OF THE THREAD 
WORMS REPORTED FOR MAN. 
By Ch. Wardell Stiles, Ph. D., 
Chief of Division of Zoology, Hygienic Laboratory, U. S. Public Health and Marine- 
Hospital Service. 
(Figs. 26-34.) 
Of the zoological names used by plwsicians, the generic name 
Filaria is one of those most commonly quoted. As used both b}^ 
zoologists and by physicians, this name has been made to act as a 
generic catch-all for slender roundworms which could not be definitely 
determined. 
Recently an apparently new species of roundworm {Agamojllaria 
georgiana) from a superficial sore on the ankle of a negress was sent 
to me by Dr. St. J. B. Graham, of Savannah, Ga., for determination, 
and upon trying to classif}" it I found that it could easih^ be placed 
in the genus Filaria as generally understood. From a systematic 
viewpoint this Avas uiisatisfactoiy, and this fact led me to trace the 
history of the genus Filaria. The results obtained have a bearing 
upon the parasites of man and part of them are herewith published in 
the hope of aiding' to clear up this group of parasites, so little under- 
stood zoologically despite the enormous amount of literature which 
has appeared upon the subject. 
The genus Filaria Avas established in ly87, b}" Mueller. In the 
original publicatioif Mueller did not mention any specific names, but 
he referred to a number of parasitic Avorms in A^arious animals, and 
comparing his bibliographic references with Gmelin, lT90a, T is clear 
that he classified the following worms in his new genus: 
A. In mammals: 
1. Filaria leonis Gmelin, 1790a; this form has been viewed since 1809 as a species 
inquirenda. 
2. F. leporis Gmelin, 1790a; this form has been viewed since 1809 as a species 
inquirenda. 
3. F. martis Gmelin, 1790a; of the three original filariue of mammals, this species 
alone has been found and described on seA'eral occasions since 1790. It apparently 
contained Gvo species. Of these, Filaria mustelarum [jndmonqlisl has been sepa- 
rated as the type of Filaroides, and the remaining form has been renamed Filaria 
mustelarum subcutanea 1819, F. quadrispina 1851, and F. perforans 1858. 
B. In birds: 
4. F. gallinse Gmelin, 1790; eliminated from Filaria since 1803. 
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