689 



1886. Beddard, Report on the Isopoda, collected by H. M. S. Challenger. 

 1897. Benedict, Arcturidae in the U. S. National Museum. Proceedings of the 



Biological Soc. Washington. 

 1899. Richardson, Isopods of Pacific coast of N. America. Proceedings of the 



U. S. National Museum. XXI. 

 1902. Hodgson, Crustacea, Report on the collections of Natural History made in 



the antarctic regions during the voyage of the »Southern Cross«. 



7. The type-species of certain genera of parasitic Flagellates, 

 particularly Grassi's genera of 1879 and 1881. 



By Ch. Wardell Stiles, Ph. D., Zoologist, U. S. Bureau of Animal Industry. 



eingeg. 21. August 1902. 



In a recent study of the literature of the parasitic flagellates of 

 man and animale, considerable difficulty was experienced in following 

 the generic synonymy because authors had failed to designate types for 

 the new genera they proposed. Two papers in particular presented 

 confusion, namely, Grassi's important publications of 1879 and 1881. 

 In order to have a definite basis for certain species with which I was 

 dealing, it became necessary to establish types for the genera in 

 question, and the results are herewith published. 



The type-species of Cimaenomonas^ 1881. 



Grassi (1881, p. 141, 154 — 160) proposed this genus with the 

 diagnosis: "Con un flagello quasi costantemente rivolto all' indietro 

 ed agitantesi sulla superficie del corpo, in modo di far nascere l'idea 

 di un orlo ondeggiante, o d'una serie di ciglia vibratili." While he 

 mentions several forms as belonging here, he gives only one, namely, 

 C. hatrachorum (Perty), as a binomial. This species should be taken 

 as type, as it is clear that he had this form particularly in mind. His 

 figures clearly show that he was dealing with either a Tricomonas 

 Donné, 1837 or a Trichomastiz Blochmann, 1884. Blochmannhas 

 placed this parasite in the genus Tricomonas where it is retained by 

 Doflein, 1901. Biitschli (1884) also takes Cimaenomonas as a syno- 

 nym of Tricomonas ^ and authors generally look upon Tricomonas ha- 

 tracJiorum Perty as a Tricomonas (see Stein's, 1878, figures). 



The type-species oi Dicer comonas and Monomorphus^ 1879. 



Grassi (1879, p. 446, 448) proposed the genus Dicercomonas^ 1879. 

 [not Diesing 1856], with the diagnosis "a coda bifida" and divided 

 the group into two subgenera, as follows: Monomorphus^ 1879, "si 

 presenta sotto una sol forma"; only, hence type species, M. ranarum^ 

 with '•'■ Hexamita ranarum Duj." {_= Hexamita intestinalis Dujardin] as 



