1920] Kofoid: Nomenclature of Human Intestinal Flagellates 161 



(1878) arachnoid. In his later paper Grassi changes the name from 

 Dimorphus muris to Megastoma entericum, since "la denominazione 

 Dimorphtts potrebbe dar luogo ad un equivoeo e I'altra muris ora e 

 diventata insufficieute. " Megastoma, as Blanchard (1888) indicated 

 when he proposed the new generic name Latnhlia, had already been 

 preoccupied in no less than four instances cited above. 



Prior to Blanchard 's (1888) erection of Lamhlia the genus Giardia 

 had been established by Kunstler (1882, 1883a, h) for a species from 

 the intestine of tadpoles. The human species is a member of this genus 

 Giardia as Alexeieff (1914) has shown. Doflein's (1916, p. 628) 

 objection to Giardia is in reality an objection to the Code of Nomen- 

 clature and to the just ethical claims of priority on the part of 

 Kunstler and Alexeieff, and to sound morphology as applied to 

 classification. 



The generic term Lamblia is, therefore, as Alexeieff (1914) has 

 recently shown, not tenable, and Giardia Kunstler must be substituted 

 for it on the grounds of priority if due regard is had to the rules of 

 nomenclature. This was regrettable from the fact that the term 

 Lamblia had become entrenched by the custom of many compilers in 

 both biological and medical literature, especially in textbooks and 

 general treatises. 



Some of the grounds for the inclusion of Lamblia (Megastoma) in 

 Giardia were noted by Grassi and Schewiakoff (1888) when, in their 

 discussion of the evident close relationships which they clearly recog- . 

 nized of the two genera, Megastoma Grassi and Giardia Kunstler, they 

 based their rejection of Giardia upon the apparent absence of the 

 cytosome, which was not demon.strated in Kunstler 's (1883) figures or 

 mentioned in his earlier discussion (1882, 1883). 



However, in Kunstler and Gineste's (1907) later paper this struc- 

 ture is definitely described and figured in Giardia alata, sp. nov., also 

 from the tadpole and probably the same species as G. agilis. In any 

 event Giardia is recognized by its author as possessing the very organ 

 whose apparent absence led to the generic recognition of Megastoma 

 and of its successor Lamblia. 



In 1907 Kunstler and Gineste discuss the synonymy of the three 

 genera, Megastoma, Giardia, and Lamblia, and although they recog- 

 nize the equivalence of the organelles of Giardia and Lamblia, they 

 conclude, erroneously we believe, that both genera should be main- 

 tained "a la fois" although the only differences they can find are in 

 proportions and size, distinctions which in the general experience of 

 protozoologists are valid only for the separation of species. 



