370 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



Cochlodinium helix (Poueliet) Lemm. 



Plate 9, figure 92 ; text figure HH, 8 



Gynmodinium helix Pouehet (1887), pp. 94^96, fig. 1. 



(?. helix, Sehiitt (1895), pp. 59, 71, pi. 24, figs. 77j_5 (fig. 77^ is Cochlodinium schuetti 



nom. sp. nov.). 

 Cochlodinium helix, Lemmermaun (1899), p. 360. 

 Gymnodinium helix, Entz, Jr. (1907), p. 11; (1909), p. 246. 

 Cochlodinium helix, Paulsen (1908), p. 103, fig. 143. 

 C. helix, Lebour (Idllb), p. 103. 



Diagnosis. — A small species with subovoidal asymmetrical body, its length 

 1.42 trausdiameters ; girdle a descending left spiral of 1.5 turns, displaced 0.65 

 transdiameter ; sulcus with apical and antapical loops and a torsion 0.8 turn; 

 color, dull yellow green. Length, 54/^. Atlantic off Concarneau, France; 

 Phinouth Sound, England, August; Pacific off La Jolla, California, July, 

 August. 



Description. — The body is irregularly subovoidal, broad aiid asjonmetrieal posteriorly, nearly 

 circular in cross-section, its length 1.42 trausdiameters at the widest part in the lower hypocone. 

 The anterior end is tapering, the posterior broad, the posteroventral face drawn out into a flap- 

 like extension on its morphological right side, giving to the body a sinistroventral excavation, 

 with tlie dorsal side strongly convex. The epieone and hypocone are subequal in size. The 

 epicoue is convex-conical, about 45° anteriorly, with blunt apex. It has a lengtli from the 

 proximal and distal ends of the girdle of about 0.21 and 0.84 respectively of the total length of 

 the body. The hypocone is broader than the epieone, less symmetrical, the dextroventral face 

 drawn out into an outstanding flap or lobe, still further marked off posteriorly by the deep 

 sulcal notch. 



The girdle is a descending left spiral of 1.5 turns, displaced about 0.65 transdiameter. The 

 anterior part of its course is nearly transverse, turning posteriorly on the left side at an angle 

 which flattens to a nearly transverse plane at the dorsal margin, crossing the right transversely 

 and turning posteriorly around the outstanding flap which is composed of portions of both 

 epieone and hj'pocone. The furrow has a width of less than 0.05 transdiameter and is lightly 

 impressed with rounded borders. 



The sulcus invades the epieone in a short loop which may partly encircle the apex or ma}' 

 terminate below the right side. It passes posteriorly in a left spiral direction, its torsion about 

 0.8 tui-ns. It deeply constricts the body in the interciugular area, lying at the base on the left 

 side of the outstanding flaplike portion of the body. It meets the distal end of the girdle at the 

 posterior point of emergence of the flap from the main body. The furrow is somewhat narrower 

 than the girdle. The anterior and posterior flagellar pores are found at the anterior and posterior 

 junctions of the girdle and sulcus respectively. 



Tlie nucleus is spherical to ellipsoidal in outline and is located in the posterior portion of the 

 body. It is filled with fine, moniliform chromatin strands. Its axis is about 0.4 transdiameter 

 in length. 



The long, sacklike pusules opening into each flagellar pore are connected at their extremities, 

 forming a tubular canal between the two openings. The cytoplasm is finely granular. The 

 centroanterior portion of the body was occupied by a pale dull yellow green food mass. Blue- 

 green spherules are usually abundant in the peripheral zone. The general color of the organism 

 is dull yellow green with a tinge of orange in the posterior part. A thin-walled, hj-aline, nearly 

 circular cyst enclosed the organism. 



