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WHAT IS THE GENUS LEPTOMONAS KENT? 
By EDWARD KINDLE, Ph.D., 
Beit Memorial Research Fellow. 
{From the Quick Laboratory, Cambridge.) 
The nomenclature of the parasitic Hagellates of invertebrates is in 
such a state of chaos at the present time, that I have collected the 
history of the three more important genera Leptomonas, Herpetomonas, 
and Crithidia, in the hope that it will end the controversies which 
surround the application of any one of these names. 
The first of these flagellates to be described was Herpetomonas 
muscae-domesticae. In the year 1851, Burnett (1851) published a short 
note on the result of his investigations concerning the structure and 
nature of the genus Bodo. In this article there is a brief mention of 
the fact that flagellates were found parasitic in the alimentary canal of 
the common house-fly, and Burnett proposed for these parasites the 
name Bodo muscae-domesticae. 
Under the name Bodo muscarum, Leidy (1856) briefly described 
a flagellate which he found frequently occurring in the intestine of 
Musca domestica, often in immense quantities. 
Stein (1878) united Bodo muscae-domesticae Burnett and B. musca¬ 
rum Leidy, but placed the parasite in the genus Cercomonas and under 
the title of Cercomonas muscae-domesticae this flagellate is described 
and figured (PI. I, pt. 2, figs. 1-4). According to Stein’s description 
this parasite possesses a remarkable degree of flexibility, and therefore 
it is a little doubtful whether it can be identified with the Herpetomonas 
muscae-domesticae of Prowazek (1904). 
Finally Kent (1881) established a new genus, Herpetomonas, for the 
reception of this form. The rat trypanosome {T. leivisi) was also 
provisionally included, but the parasite of the house-fly was designated 
as the type of the genus. 
