KOFOID AND SWEZY: UNARMORED DINOFLAGELLATA 361 



It is nlso peculiar in the germs Cochlodimnm in the degree of its eetoplasmic 

 differentiation. This differs from the peripheral organization of the cytoplasm 

 in Gijmuodiniiim, as developed in G. dogieJi (fig. AA, 8), in which the vacuolate 

 layer is superficial, with the convexities of the individual alveoli roughening 

 the surface of the hody. In Cochlodiniinii rJarissimviH the alveoli are more 

 deeply imbedded, the pellicle presenting a smooth surface. 



Cochlodinium conspiratum sp. nov. 

 Plate 3, figure 29 ; text figure GG, 10 



Diagnosis. — Small species, body l)roadly ellipsoidal to obovate, flattened and 

 incised on the left, arched on the right; lengtli 1.2 transdiameters ; girdle a 

 descending left spiral of 1.8 turns, displaced 0.7 transdiameter ; sulcus with 

 apical and antapical loops and torsion of 0.8 turn; ])lasma chalcedony yellow. 

 Length. ?>9i^. Pacific ofl La Jolla, California, July. 



Description. — The body is rotund, subellipsoidal to obovate, widest anteriorly, with its length 

 exceeding its transdiameter by only 0.2. Left face flattened, deeply incised at three points by 

 girdle and suleu.s, right side more rotund. The epieone exceeds the hypoeone in length by 0.2 

 total length. The epieone is broadly rounded at the apex as a somewhat flattened hemisphere. 

 It has a length at the proximal and distal ends of the girdle of 0.25 and 0.88 respectively of the 

 total length of the body. The hypoeone is somewhat narrower than the epieone with a broad, 

 almost flattened but much contracted antapex. Its length at the proximal and distal ends of the 

 girdle is 0.75 and 0.12 respectively of the total length of the body. 



The girdle forms a descending left spiral of 1.8 turns. It joins the sulcus anteriorly 0.25 

 of the total length of the body from the apex. Its first 0.75 turn is almost horizontal or some- 

 what deflected anteriorly. It then turns abruptly posteriorly 45° from the horizontal for 0.5 

 turn, then flattens again almost to the horizontal for the last 0.6 turn around the body to meet 

 the sulcus distally at the right of the antapex. Except in the middle part of its course on the 

 right dorsal side, it lies in a narrow, deep depression or trough with rounded borders. The 

 width of the furrow is 0.07 transdiameter. The anterior flagellar pore is located at the anterior 

 junction and the posterior flagellum slightly below the distal junction, on opposite faces of the 

 body. The transverse flagellum traverses only one turn of the girdle and the posterior flagellum 

 is 0.75 of the length of the body in length. 



The sulcus invades the epieone in a curving line to the left of the apex. Below the anterior 

 pore it takes a descending left spiral course of one complete turn, ending near the antapex. 

 After joining the girdle near the antapex its antapical loop makes 0.25 of a turn around the 

 antapex in a horizantal plane. 



The nucleus is broadly ellipsoidal and is located in the posterior half of the body. Its major 

 and )ninor axes are 0.5 and 0.4 transdiameter in length respectively. Coarsely beaded chronuitin 

 threads, eight across one face, traverse its shorter axis. 



A small, sacklike pusule opens anteriorly into the anterior flagellar i)ore. The cytoplasm is 

 very clear and transparent, though filled with numerous inclusions. Six large, subspherical 

 food masses filled the center of the body. These; varied in color from blue to grey green. Mingled 

 with these were a few minute oil droplets and refractive gi-anules. The color is a pale chalcedony 

 yellow with a tinge of yellow ochre near the girdle. The proximal border of the girdle was 

 marked by a bright yellow-green line from which the color diffused into the adjacent cytoplasm. 



