691 



only M. hominis and M. coronellae. The former is a Tricomonas, to 

 which genus it has been transferred by several authors. This leaves 

 M. coronellae as type of Monocercomonas. 



This ruling by elimination agrees with the action taken by Dof- 

 lein (1901) in placing this species in Monocercomonas. 



The type-species of Monomita ^ 1881. 



This genus is based upon Cercomonas muscae-domesticae Stein, 

 which Kent (1880) took as type of the genus Herpetotnotias 1880. 



The type-species oî Retortamonas^ 1879, and Plagiomonas, 1881. 



A number of recent authors retain Grassi's (1881) genus Plagio- 

 monas, which he based upon the single (hence type) species P. gryllo- 

 talpae, and to which he gave the diagnosis "In forma di una sorta; 

 estremità posteriore affilata e semplice", while his figures in 1881 show 

 that the anterior extremity possesses two flagella, similar to the con- 

 dition found in Bodo. D of lein (1901) in fact, transfers the species 

 to Bodo. 



The generic name Plagiomonas is not valid, even if the genus is 

 recognized as distinct, for G ras si in 1879 proposed the genus Retorta- 

 moiias with, thiss ame species (gryllotalpae) as only, hence type, species. 



The type-species oî Schedo ac ere omonas Grassi, 1879. 



Grassi (1879, p. 446, 448) originally placed here the following 

 species: 



1) Schedoacercomonas grtjllotalpae, which he transferred in 1881 to 



Monocercomonas as M. insectorum. 



2) Schedoacercomonas melolonthae , which he transferred in 1881 to 



Monocercomonas as M. insectorum. 



3) Schedoacercomonas caviae, of which I have failed to find a later 



mention. 



4) Schedoacercomonas muscae-domesticae , with Cercomonas muscae-do- 



mesticae as definite synonym. Kent (1880) made this species 



type 0Î Herpetomoiias , and Grassi based upon it the genus Mo- 



nomita., 1881. 



Thus, S. caviae remains type by elimination, and unfortunately 

 Grassi gave no specific characters for this form. Schedoacercomonas 

 therefore rests simply upon the short diagnosis "quasi senza coda", 

 with type in the guinea pig, as indicated by the name caviae. 



Types of other genera of parasitic flagellates. 



In order to settle the question of type-species for certain other 

 genera ofparasitic flagellates, attedi tion maybe directed to the following: 



