96 University of California Publications in Zoology [Vol. 18 



not have been responsible for its subsequent complete disappearance 

 from the literature of protozoology. The articles pertaining to it were 

 in part published in the Zoologischer Anzeiger, the most widely dis- 

 tributed zoological journal in the world. But Biitsehli in his Thier- 

 reich monograph of the Protozoa, then in process of publication (1883- 

 1889), omits all reference to Erytkropsis. Pouchet who published in 

 France a series of papers on dinoflagellates and rediscovered the 

 ocellus in organisms now referred to Pouchetia, a genus closely related 

 to Erytkropsis, makes no note of Hertwig's species. Neither does 

 Schiitt in his Plankton Expedition monograph (1895) note its exist- 

 ence, although he describes, as Poucketia cornuta and P. cocklea, two 

 species which belong to the genus Erytkropsis. This relationship, how- 

 ever, was in part obscured by the reduction or absence of the prod in 

 Schiitt 's specimens. The ocellus, it would seem, was sufficient to have 

 established the relationship. In his later (1896) assemblage of the 

 genera of the "Peridiniales" in Engler and Prantl's Pflanzenfamilien, 

 Erytkropsis is again missing. 



It was not until Delage and Herouard (1896) assembled the Pro- 

 tozoa in their Traite de Zoologie Concrete that the genus was recogn- 

 ized as valid and placed in its true relationship. These authors, 

 impressed by its similarity to Poucketia, cautiously admitted it into 

 an appendix to the Dinoflagellata. 



They fell, however, into one misrepresentation of Hertwig's figures, 

 which affords the starting point for Faure-Fremiet 's later erroneous 

 allocation of the flagellum. In discussing the girdle and its flagellum 

 they state : 



Le filament en ressort a boudin n 'a rien de commun avec une zone adorale 

 tandis qu'il represente exactement le fouet transversal d'un Peridinien (il faut 

 noter cependant que Hertwig n'est pas tres afl&rmatif siir la question de savoir 

 si la portion qui occupe la gouttiere est ou non continue avec celle qui est logee 

 dans la partie superieure du sillon longitudinal, et que ce fouet, par une exception 

 unique, suivrait le sillon de gauche a droite. Enfin le gros appendice serait le 

 fouet vertical). 



The basis for this interpretation is not clear as will be seen in our 

 reproduction of Hertwig's (1884) figures (figs. 9, 10). In so far as 

 the main encircling spiral filament, as shown in the figures, is con- 

 cerned, it might run in either direction around the body, for as a 

 matter of fact, neither end is figured, and the short strand seen in one 

 of Hertwig's figures (pi. 6, fig. 2, reproduced in our figure 10), may 

 be the amoeboid uppermost end of the sulcus and not a flagellum 

 connected with any part of the girdle. 



