KOPOID AND SWEZY: UNARMORED DINOFLAGELLATA 365 



The epicone exceeds the hypocoiie by 0.08 total length and contains parts of all three 

 lobes. Its length at the proximal and distal ends of the girdle is 0.33 and 0.75 respectively of 

 the total length of the body. The apex is hemispherical. The hypocone has a length of 0.67 

 and 0.25 total length respectively at the two ends of the girdle and a subhemispherical antai)ex, 

 somewhat deflected ventrally and slightlj- flattened on the ventral face posteriorly. The deep 

 concavity affects the intercingular region of these two segments of the body. 



The girdle pursues a somewhat erratic course owing to the concavity and torsion of the body. 

 It forms a descending left spiral with a total displacement of 0.45 total length. From its 

 junction with the anterior end of the sulcus it makes 0.5 turn in the horizontal plane, turns 

 posteriorly at the right face along the arched dorsal side of the middle lobe, and upon its contact 

 with the posterior lobe turns again to an almost horizontal, somewhat sinuous course for the 

 last 0.75 turn. Its total course is thus about 1.5 turns. The amount of the torsion and resulting 

 overlap may be greater than this, as is indicated by the course of the surface striae, but its 

 determination is obscured by the ventral concavity. The furrow is 0.06 transdiameter in width, 

 and is not deeply impressed. 



The sulcus does not extend anteriorly above the junction with the girdle and is hidden 

 posteriorly in the concavity. It makes about 0.5 turn of a descending left spiral, continues 

 posteriorly below its junction with the distal end of the girdle about half way to the antapex. 

 Its total length in the anterior-posterior direction is 0.56 total length or more, of which 0.42 is 

 intercingular. The anterior pore is at the anterior junction and the po.sterior one about one 

 width of the furrow below the posterior junction. 



The nucleus is a homogeneous ellipsoidal body located almost transversely in the extreme 

 anterior end of the body. Its axes are 0.74 and 0.50 transdiameter in length respectively. A 

 small spherical pusule opens by a short canal anteriorly into the anterior flagellar pore, and 

 a smaller one also opens anteriorly, instead of posteriorly as usual, into the posterior pore. There 

 were no chromatophores, food balls, oil globules, or rhabdosomes. The cytoplasm was remarkably 

 clear and free from coarse vacuolation. Tlie surface was striate with fine greenisli yellow lines 

 running longitudinally parallel to the morphological axis from apex to antapex. Scattered 

 along their courses at somewhat regular intervals are numerous orange globules of varying size. 

 They are somewhat more crowded near the girdle and the apices of the body. 



Dimensions. — Length, 155m; transdiameter of terminal lobes, 70m; axes of 

 mtcleus, 50m and 37m. 



Occurrences. — One individual taken 4 miles off La Jolla, California, on 

 July 27, 1917, in a haul from 80 meters to the surface in a surface temperature 

 of 21?9C. 



Activities. — Both flagella were normally active and the animal moved inter- 

 mittently with a jerking motion. There was no evidence of abnormalit}'' in its 

 activities. The body was exceptionally plastic and labile. 



Comparison. — This is one of the most aberrant types of the genus Cochlo- 

 flinium. not far from G ijrodinium in the amount of torsion, and striate, as is 

 often the case in species of that genus. The location and axial position of the 

 nucleus, together with the deep concavity and distortion of the body, suggests 

 the possibility that this was a form in tlie telophase of binary fission, but no 

 second nucleus was present in the translucent posterior end. The form also 

 suggests mechanical distortion, but there was no change prior to those which 

 lead to cytolysis and there were none of those evidences of nmtilation or ab- 

 normality which are readily detected. The form is bizarre, but not clearly 

 abnoi'iiial, and its activities were of the normal type. 



