112 MEMOIKS OF THE UNIVERSITY OF CALIFORNIA 



Tlie body is asymmetrical with no appreciable torsion in either genus. The nucleus is gen- 

 erally found near the center of the body with its chromatin contents arranged in characteristic 

 raoniliform strands. Nutrition is holozoic or saprophytic. 



This family contains two genera, Protodinifer and Oxyrrhis, with a single species in each. 



Key to Genera of Protodiniferidae 



1. Girdle short, faintly outlined, tentacle long, flagella anterior Protodinifer gen. nov. 



2. Girdle nearly or quite 1 circumference in length, tentacle short, flagella ventrolateral 



- Oxyrrhis Dujardin 



PROTODINIFER gen. nov. 



Plate 7, figure 74; text figure R, 2 



Diagnosis. — Protodiniferidae with anteroventral tentacle and sulcus, feebly 

 developed anteriorly located girdle, long threadlike transverse and short longi- 

 tudinal flagellum; no lens or pigment; no large hydrostatic vacuoles, small 

 flagellates, marine. 



This genus contains two species, both marine, Protodinifer tentaculatum 

 sp. nov., the t^^e species of the genus, and P. marimim (Lohmann). The latter 

 is provisionally transferred here from Rhjincliomonns on the basis of its morph- 

 ological features other than the very essential prunitive girdle and sulcus and 

 the beaded chromatin in the nucleus, features which are as yet undetermined 

 in this species. 



The genus Bltynclwmonas Klebs is based on a species {R. nasuta) from 

 fresh water whose nucleus is of the vesicular t^^pe. This flagellate has an 

 as^anmetrical pro])oscis-like tentacle and a trailing flagellum. It thus super- 

 ficially resembles Protodinifer, whose relationships to the Dinoflagellata are 

 revealed by its nucleus with its moniliform chromatin network. 



Key to the Species op Protodinifer 



Tentacle stout, length of body 54;^ tentaculatum sp. nov. 



Tentacle slender, length of body 12-AOn marinum (Lohmann) 



Protodinifer tentaculatum sp. nov. 



Plate 7, figure 74 ; text figure R, 2 



Diagnosis. — A small species with fusiform body, its length 2.45 transdi- 

 ameters; girdle near apex, feebly developed and evanescent; sulcus scarcely 

 evident ; longitudinal flagellum short ; apex modified in the form of a stotit 

 mobile tentacle 0.22 of length of body in length; color greenish grey to pale 

 ochraceous. Length 54;^. Pacific off La Jolla, California, July, August. 



