188 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



Small, club-shaped pusiiles open into each flagellar pore. The cytoplasm was unnsually free 

 from cell inclusions such as food bodies, vacuoles, etc. A small, irregular, dark green mass was 

 found close beside the nucleus and farther anteriorly, another, slightly larger, of a neutral grey 

 with a dark border. The cytoplasm is finely granular. The general color is old gold, quite deep 

 posteriorly, shading to pale king's blue at the anterior end, with tones of light green and pearl 

 grey through the girdle region. No striae or other markings could be detected on its surface. 

 A thin hyaline cyst somewhat larger than the body, and closely following its contour, enclosed 

 the organism. 



Dimensions. — Length, 62;^; trausdiaineter, 43/*; axes of nucleus, 28/* and 18/^; 

 length of cyst, 66/*. 



OcciTERENCE. — A single individual was observed August 20, 1917, from a 

 haid made 0.75 of a mile off La Jolla, California, from 80 meters to the surface, 

 and in a surface temperature of about 22° C. 



Comparisons. — This species, because of the comparative simplicity of its 

 orgaiiization and lack of surface markings, falls within the subgenus Gymno- 

 dinium. sensu strictu. Its coloring suggests that of G. amphora (fig. AA, 6), 

 but it differs greatly from that species in all other respects. In proportions 

 it approaches rather distantly some of the biconical species of the subgenus 

 Lineadinhim (fig. Y), but lacks the striae which characterize that subgenus. 

 It is nearest G. violescens sp. nov. (fig. X, 11), but is wholly different in color, 

 has less displacement of girdle, and a fuller In'pocone. 



Gymnodinium aureum sp. nov. 



Plate 1, figure 5 ; text figure Y, 3 



Diagnosis. — A medium sized species Avith subovoidal body pointed poster- 

 ioi'ly, its length 1.84 transdiameters ; girdle premedian, displaced twice its o-mi 

 width; sulcus extending from near a])ex to antapex; surface striate; color 

 strontium yellow. Length, 83/*. Pacific off La Jolla, California, July. 



Description. — The body is ovoidal, subtruncate-acuminate anteriorly, tapering to a slender 

 point posteriorly, widest through the epicone, its length 1.84 transdiameters at the widest part 

 and its dorsoventral diameter 0.85 transdiameter. The hypocone exceeds the epicone in size, 

 being longer by 0.18 of its length. The epicone is conical in outline (70°). Its apex is truncate- 

 acuminate with a median and two lateral elevations on the summit formed by two parasagittal 

 creases across the apex. Its length is about 0.39 of the total length of the body, with the right 

 side extending posteriorly in a slender point with a length of 0.47 of the total length. The 

 hypocone is longer, less symmetrical than the epicone and is drawn out distally to a slender, 

 pointed, ventrally flexed antapex. It has a width at the girdle equal to the width of the epicone, 

 but is much narrower posteriorly. 



The girdle is premedian in position, its proximal end meeting the sulcus at a distance from 

 the apex of 0.39 of the total length of the body. It passes around the body in a nearly trans- 

 verse direction for about 0.8 of its course, the latter part turning posteriorly so that the distal 

 end is displaced about twice its own width. The furrow is wide, about 0.08 transdiameter, its 

 distal end narrowed to less than half that width, and is deeply impressed with smooth, over- 

 hanging borders. The sulcus is somewhat variable in its length. It may invade the epicone a 

 short distance only or may reach the neighborhood of the apex. The furrow is deep, varies 



