484 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



defense has but served to confirm liis eonvietion that Ms exposure of Hertwig's 

 ei'ror is sound, and that Eri/th ropsis is only a Spastostjjla which had been killed 

 in the act of eating the ocellus of a medusa. 



Some months after Yogt's exposure, Metchnikoff (1885) published a brief 

 note stating that he had seen an organism, which resembled that deseril)ed by 

 Hertwig, in the living material taken in the tow net off Madeira, and had made 

 a lu'ief reference to it in 1874 in a short note in Russian concerning his "Reise 

 nach iSIadeira." He suggested its affinities to the suctorian Ophnjodcndron. 



Thereafter Erijfhropsis disappeared from zoological literature, as Yogi 

 (1885) had advised, for nearly a score of years. It does not appear in Biitschli's 

 (1881-89) monograph of the Protozoa, or in any of the monographic treatises 

 or text books written since Hertwig's jjaper was published, with the single 

 exception noted below. Nor did Schiitt, either in his monograph (1896) of 

 the Peridiniales or in his Plankton Expedition report (1895) make any mention 

 of Hertwig's discovery. This is perhaps not strange since no one had as yet 

 suggested its affinities to the Dinoflagellata, and no investigator of this group 

 or subsequent observer had as yet seen any species of the new genus or verified 

 Hertwig's discovery. Pouchet (1884, 1885a, h, 1886«, h, 1887) had in a series 

 of papers called attention to the ocellate Dinoflagellata but overlooked Hert- 

 wig's related Erytli ropsis. It was still under the cloud of suspicion raised by 

 Vogt's criticisms, so that its true relationship was as yet unsuspected. The latter 

 is probably the case with Schiitt's omission, since he describes, as Ponchetia 

 cochlea and P. cor nut a, two organisms which exhibit unmistakable resemblances 

 to Erytliropsis. They both lacked "tentacles." However, this is a condition 

 frequently observed, in our experience, in other species of Erytliropsis in which 

 the tentacle or prod is often dropped off prior to cytolysis. 



The genus remained in this neglected condition until 1896, when Delage and 

 Herouard in the course of their reorganization of the genera of the Protozoa 

 in their Traite de Zoologie Concrete brought this genus into relation with the 

 Dinoflagellata. They were still cautious, however, and admitted it only in an 

 appendix to this group, stating: "II nous semble qu'il y a une autre maniere 

 de voir plus vraisemblable que les precedentes et que nous hasarderons tant 

 elle nous semble probable, mais sous toutes reserves et sans reeonnaitre le danger 

 qu'il y a a formuler une opinion sur un etre que Ton n'a jdu examiner." 



It was not until 1904 that Pavillard (1905), himself an investigator of the 

 Dinoflagellata, found at Cette on the Mediterranean a single individual which 

 he recognized as an Erythropsis. He had a brief opportunity to sketch the 

 anunal and concluded that it was Hertwig's species rediscovered. He also for 

 the first time accorded it unquestioned place with the affiliated genera Pouclictia 

 and Gymiiodinium; but, owing to the paucity of his material, he did not recog- 

 nize that his species was distinct from that of Hertwig, and that Schiitt (1895) 

 had previously seen two other species of the genus, Init, not recognizing 

 Erytliropsis as a dinoflagellate, had placed these species in PoiicJietia. 



