384 MEMOIKS OF THE UNIVERSITY OF CALIFORNIA 



The sulcus forms a short loop on the epieone, ending below the apex. Posterior to the 

 anterior pore it takes a descending left course which makes 0.5 turn in reaching the antapex. 

 It is narrow and deeply impressed with high-rolling borders. This with the girdle throws the 

 ventral surface into a series of three rounded lobes. 



Tlie nucleus is large, ellipsoidal and placed slightly anterior to the central portion of the 

 body. Fine, moniliform parallel chromatin strands traverse a course obliquely across its major 

 axis. Its major and minor axes are 0.6 and 0.48 transdiameter in length respectively. 



The cytoplasm is very clear and transparent with but few inclusions. Near the periphery 

 are a number of refi'active spherules and blue-green oil droplets. A food mass, yellow ochre 

 in color, was found in the center of the body adjacent to the nucleus. The color is mingled 

 yellow green and pearl gre3\ 



Dimensions. — Length, 26;^ ; transdiameter, 25m ; axes of nucleus, 15f^ and 12j". 



Occurrence. — A single individual was taken July 25, 1917, with a No. 25 

 net, 11 miles off La Jolla, California, in a haul from 80 meters to the surface 

 and in a surface temperature of 21 ?S C. Two individuals were taken August 8 

 in a haul 4 miles off La Jolla, from 80 meters to the surface and in a surface 

 temperature of 22?5 C. 



Comparisons. — This is the shortest and the smallest species in the genus 

 Cochlodinimn, and is most contracted posteriorly. Its rotundity, however, 

 makes it nearly equal in size to C. pnlclieUum sp. nov. (fig. HH, 16), the latter 

 having a greater length but about half its width. It belongs in C. miniatum 

 group of the subgenus Cochlodinium. 



Cochlodinium vinctum sp. nov. 



Plate 2, figure 15 ; text figure HH, 3 



Diagnosis. — Medimn sized species; body as}amnetrically ovoidal or rotund, 

 dorsally arched, length 1.4 transdiameters, girdle a descending left spiral of 

 1.50-1.65 turns, displaced 0.57-0.62 total length, sulcus with anterior and pos- 

 terior loops, torsion 0.50-0.65 turns; plasma very clear, pale glaucous blue, 

 sometunes tinged with yellow. Length, 50-75^. Pacific off La Jolla, California, 

 July, August. 



Description. — The body is asymmetrically ovoidal to rotund in shape, according to the view. 

 The more rotund forms may also owe their breadth in part to the great mass of cell inclusions 

 present in such individuals. The anterior end is often a trifle broader and rounded, the posterior 

 slightly narrower and also rounded, and the spiral ventral face deeply channeled and some- 

 what flattened, while the dorsal is arched, in the extreme condition almost hemispherical. The 

 epieone and hypocone are subequal. The epieone has a length at the proximal and distal ends 

 of the girdle of 0.18 and 0.65 respectively of the total length of the body. Its apex is sub- 

 hemispherical with the flatter slope on the right side. The hypocone has a length at the proximal 

 and distal ends of the girdle of 0.82 and 0.35, total length of the body. The antapex is sub- 

 hemispherical with the flatter slope at the morphological right side of the sulcus. It is some- 

 times notched by the end of the sulcus. 



The girdle joins the sulcus anteriorly at 0.18 of the total length of the body from the apex. 

 It forms a descending left spiral of 1.6 turns, displaced about 0.57-0.62 diameter. It is deeply 

 impressed, especially on the left side, forming witli the siilcus a series of deep lobes on the 



