KOFOID AND SWEZY: UNARMORED DINOFLAGELLATA 245 



Poiicliet's description of this form leaves the important species character- 

 istics, the relation of girdle and sulcus, undetermined. Paulsen (1908) suggests 

 the possibility of this being a swarm spore. It differs sufficiently from the 

 other forms deseriljed to be regarded only tentatively as a valid species. Its 

 excej)tionally small size requires verificatiou. 



Gymnodinium puniceum sp. nov. 



Plate 5, figure 51 ; text figure Z, 5 



DiAGxosis. — This is a large species with subovoidal l^ody, its length L57 

 transdiameters ; girdle premedian, without displacement; sulcus extending 

 from near apex to antapex ; surface sparsely furrowed ; color, onion-skin pink. 

 Length, 110/^. Pacific off La JoUa, California, August. 



Description. — The body is subovoidal in shape, with broad apices, widest posteriorly, its 

 length 1.57 transdiameters at the widest part. The hypocone greatly exceeds the epicone in size. 

 The epicone forms a slightly irregular dome with broad rounded apex. The left side is more 

 convex than the right, both are slightly irregular. Its length is about 0.32 of the total length 

 of the body. The hypocone is barrel-shaped, with broad antapex. Its greatest transdiameter at 

 about its middle equals its length. The right side is convex, the left concavo-convex anteriorly 

 and convex posteriorly. The sulcal notch is deflected to the right, tlirowing the two lobes formed 

 by its borders on the dorsal side of the body, to the right of the midplane of the body in ventral 

 view. 



The girdle is premedian in position, its distance from the apex about 0.32 of the total length 

 of the body. It forms a complete circle around the body. The furrow is wide, about 0.07 trans- 

 diameter, and is deeply impressed, with its anterior lip deeply undercut and its posterior border 

 gradually rounded. Its borders are irregular, following the curves of the surface. The right 

 end of the girdle is somewliat wider than the left. The sulcus begins near the apex and extends 

 posteriorly in a slightly sinuous line to the antapex. It forms a l)road channel which fades out 

 near the apex, widens at the girdle and deepens posteriorly, witli llie overhanging borders 

 narrowing its apparent width near the posterior pore. Near the antapieal region the borders 

 become widely deflected and extend around to the dorsal surface of the body, about the deeply 

 excavated antapex. The anterior flagellar pore is found at the junction of the girdle and sulcus, 

 the posterior pore about 0.6 of the distance between that junction and the antapex. 



The nucleus is ellip.soidal, its long axis parallel with tlie long axis of the body. It is situated 

 on the left side of the body, posterior to the girdle. Its major and minor axes are 0.51 and 0.32 

 transdiameter respectively. 



A small sacklike pusule opens into the anterior flagellar i)ore. None could be detected at the 

 posterior pore. The cytoplasm is finely granular and is almost completely filled with variously 

 colored food bodies. The central part is occupied by a single large mass of a dark color. 

 Surrounding this were smaller bodies and vacuoles of varying shades of grey, yellow ochre and 

 green, with a few .small refractive spherules. Nutrition is holozoic. The general color of the 

 organism is onion-skin pink diffused througli the cytoplasm, with a slight deepening of the color 

 anteriorly and in the central part of hypocone. 



The surface of the body is marked by deep furrows, about 6 across the ventral face. The 

 surface between the furrows is raised into high, rolling i-idgcs. The fiirrows disajipear before 

 reaching the apices and girdle, but the ridges continue to the girdle and antapex, giving to the 

 borders of both a lobed appearance. 



