306 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



groups of organisms too great to suggest any close relationship between them. 

 The entire lack of any suggestive links bet\YGen tlie two groups would tend to 

 confirm our supposition that these are separate and distinct organisms. In 

 view of the lack of definite species characters both in Kiister's description and 

 in that of Jollos we place this form among the species incertae sedis until it has 

 been reinvestigated. 



Gyrodinium fulvum sp. nov. 



Plate 7, figure 70 ; text figure DD, 9 



Diagnosis. — A small species with ovoidal body Avith pointed apex, its length 

 1.87 transdiameters ; girdle a descending left sjiiral with slight overhang and 

 displacement of 0.9 transdiameter ; sulcus extending from girdle to antapex; 

 surface imevenly striate ; color, yellow ochre. Length, 62m. Pacific off La Jolla, 

 California, July. 



Description. — The body is ovoidal, rounded posteriorly, tapering abruptly anteriorly to a 

 point, its length 1.87 transdiameters at the widest part below the girdle. In cross-section the 

 body is nearly circular. The epicone and hypocone are subequal in size, though the greatest 

 length of the epicone is about 0.32 greater than that of the hypocone. Its transdiameter is 

 somewhat less. The epicone is broad and rotund posteriorly, tapering anteriorly to a slender, 

 pointed apex nearly 2 girdle widths in length. It has a length on the left and right sides of 

 0.36 and 0.85 respectively of the total length of the body. The hypocone is elongate, subhemi- 

 spherical with the antapex slightly notched ventrally bj- the distal end of the sulcus. It has a 

 length on the left and right sides of about 0.59 and 0.19 respectively of the total length of the 

 body. 



The proximal end of the girdle joins the sulcus at a distance from the apex of 0.36 of the 

 total length of the body. It follows a descending left spiral course around the body, its distal 

 end meeting the sulcus at a distance from the apex of 0.85 of the total length of the body. Its 

 displacement is about 0.9 transdiameter with an overhang of about 0.2 transdiameter. It has a 

 width of about 0.07 transdiameter and is deeply impressed, undercutting its anterior border and 

 smoothly rounding out to the posterior one. The sulcus extends from the girdle to the antapex 

 in a slight sigmoid curve. Its width is nearly equal to that of the girdle. The anterior flagellar 

 pore opens at the proximal junction of the girdle and sulcus, the posterior pore near the antapex. 



The nucleus is a spheroidal body filled with loose chromatin strands. It is located near the 

 center of the body. Its axis is about 0.48 transdiameter in length. 



The pusule of the individual figured shows a rather unusual development. It consists of a 

 large, globular vesicle nearl.y as large as the nucleus in the posterior part of the body, connected 

 with the anterior fiagellar pore by a long, slender canal. No pusule was present at the posterior 

 pore. The cytoplasm is coarsely granular. In the peripheral zone are numerous small spherules, 

 probably pigment, yellow ochre in color, with a few larger, greenish yellow bodies near the center 

 of the body. The cytoplasm is pearl grey in color. The surface of the body is striate, with the 

 number of lines on the hypocone about twice that on the epicone where there are about 22 across 

 the ventral face. The latter differ also in that every other line is slightly heavier and broader 

 than the intermediate lines. 



Di^fExsioxs. — Length, 62/^ ; transdiameter, 33/* ; axis of nucleus, 16/^. 



OccuREEXCE. — This was taken July 5, 1917, in a haul 6 miles off La Jolla, 

 California, from 80 meters to the surface and in a surface temperature of 

 21?9 C. 



