KOFOID : NEW SPECIES OF DINOFLAGELLATES. 179 



margin is straight or nearly so, horizontal, and equals the axial altitude of the 

 hypotheca in length. 



The transverse furrow is not impressed, its posterior list is absent, and it 

 forms a descending right spiral displaced distally its own width. The 

 longitudinal furrow extends but half-way to the postmargin and is very 

 narrow. 



The left intercalary plate is large. Suture lines are marked by ridges. 

 Thecal wall reticulate, with coarse, irregular, unequal polygons. 



Length, 105 /x; transdiameter, 80 ti. 



Station, 4637. 



Heterodinium fenestratum, sp. nov. 



Plate 8, Fig. 47. 



A small species of robust habit, rotund body, short incurved antapicals, 

 very coarse reticulations, and deficient posterior list to the girdle. 



The body is very robust, the length being 1.36 times the transdiameter and 

 1.6 times the dorso- ventral diameter. The epitheca is abruptly contracted from 

 the spreading girdle to a tapering apical horn which terminates in a large ob- 

 lique or squarely truncate apical pore. Its altitude is 0.70-0.75 of a transdi- 

 ameter. Its margins are in all views deeply concave. The ventral excavation 

 is not marked. The ventral area is squarish with central pit. 



The hypotheca is a little smaller than the epitheca, its altitude being about 

 0.45 of the total length. It is contracted less abruptly than the epitheca, hav- 

 ing a width of 0.55 of a transdiameter at the level of the postindentation. The 

 sides of the antapicals are nearly parallel to the main axis. The antapicals are 

 short, stout, acute. The postindentation is very shallow, being 0.2-0.26 of a 

 transdiameter in depth. The postmargin is a broad, quite regular curve. 



The girdle is wide, is displaced 1.5-2 times its own width, slightly im- 

 pressed, if at all, and bears a regular series of large reticulations. Its anterior 

 ridge is heavy and ribbed, and the posterior one is obsolete or scarcely 

 developed. 



The plates are normal. The left intercalary is very small, embracing but 

 one or two reticulations. The marked characteristic of the species is the very 

 coarse reticulations each of which has 1-10 pores. There are 17 reticulations 

 on the dorsal apical plate and 8 contiguous to the posterior margin of the 

 girdle on the dorsal side. Suture lines are marked by very wide bands. 



Length, 95-105 ti; transdiameter, 70-77 ti. 



Stations, 4730, 4742. 



Heterodinium fides, sp. nov. 



Plate 7, Fig. 45. 



A small species with constricted scoop-shaped epitheca, wide salient girdle, 

 and short, divergent, subequal antapicals. 



Body stout, its length 1.5 times the transdiameter and 2 times the greatest 



