116 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



Synoxymy. — Lolimami originally described this species as BhyncJiomonas 

 marhia. However, F. uasuta, the type species of Kleb's genus Rliijnclwmonas 

 (1892), does not have the beaded chromatin nucleus characteristic of the Dino- 

 flagellata, as shown by the investigations of Belar (1915), nor are the tentacles 

 of the two species, R. nasuta and R. marina, as nearly alike as those of Proto- 

 dinifer tentaculatnm and P. marinum. We do not know the nuclear structure 

 of Lohmann's species. We assimie on the basis of the other morphological 

 features that it will prove to be of the dinoflagellate type and make the generic 

 transfer thereon to Protodinifer. If it does not have such a nucleus it should 

 not be transferred here. 



OXYRRHIS Dujardin 



Text figure R, 3 



Oxyrrhis Dujardin (1841), pp. 346, 347, pi. 5, fig. 4. 



Oxyrrhis, Diesing (1850), p. 58; (1865), p. 79. 



Glyphidium Fresenius (1865), pp. 83, 84, figs. 4-10. 



Glyphidium. Cohn (1866), pp. 295, 296, pi. 15, figs. 36, 37. 



Oxyrrhis, Saville-Kent (1880-82), pp. 426-428, pi. 24, figs. 53-61. 



Oxyrrhis, Biitschli (1885), p. 845, pi. 45, fig. 12. 



Oxyrrhis, Senn (1900), pp. 136, 137, fig. 93; (1911), pp. 606-643, pi. 35, figs. 1-4. 



Diagnosis. — Body subovoidal, as}^lmletrically contracted on the left poster- 

 iorly; girdle postmedian, incomplete distally, lacking postmargin; sulcus 

 spreading posteroventrally, divided anteriorly by pendant tentacular lobe; 

 transverse flagellum originating to the left and the longitudinal to the right of 

 the lobe ; nucleus with beaded chromatin ; marine. 



Rel.\tioxships. — The nuclear structure with its very characteristic beaded 

 chromatin, clearly demonstrated in the researches of Keysselitz (1908) and 

 Senn (1909), establishes beyond question the dinoflagellate affinities of this puz- 

 zling flagellate. The oblique (almost transverse) fission, the subsequent chain 

 formation by the two schizonts, the posteriorly directed longitudinal flagellum, 

 and the partially developed girdle support this interpretation. There is need 

 of further research on the structure and behavior of the transverse flagellmn 

 and of the tentacular lobe. 



The dinoflagellate affinities of Oxyrrhis have been pointed out by Senn 

 (1909f/, &) on the basis of the nuclear structure and general morphology, and 

 by Jollos (1910) on the ground of the nucleus alone. This relationship was 

 first suggested, however, by Biitschli (1885), who called attention to the fact 

 that Oxyrrhis had the dinoflagellate t}T)e of nucleus and posteriori}' directed 

 flagella. He also noted the difference between the two flagella and concluded 

 that Oxyrrhis might be regarded as a form intermediate between the Cr}^to- 

 monadina on the one hand and the Dinoflagellata (Ilciuidiuiioii) on the other. 

 Unfortunately this view had not been incorporated in his earlier (1885) mono- 

 graph where Oxyrrhis was included in the Crj^ptomonadina. Delage and 



