KOFOID AND SWEZY: UNARMORED DINOFLAGELLATA 315 



Description.— The body is irregularly fusiform, widest anteriorly, its length 2.68 transdiam- 

 eters at the widest part, which is in tlie lower epicone. The epicone exceeds the hypocone in length 

 by 0.25 of its own length. It is conical anteriorly (45°) with a blunt apex. It has a length on 

 the left and right sides of 0.37 and 0.56 respectively of the total length of the body. The 

 hypocone narrows behind the girdle to about 0.5 the width anteriorly. The antapex is obliqnely 

 truncate with a small knoblike projection from the center of the truncate surface. 



The girdle begins at a distance from the apex of about 0.37 of the total length of the body. 

 It passes around the body in a descending left spiral direction and terminates at a distance from 

 the apex of 0.56 of the total length of the body, being displaced 1.06 transdiameters. The 

 furrow is wide, about 0.1 transdiameter, and quite shallow. The sulcus is not shown in Lohmann's 

 (1908) figure. 



The nucleus is an ellipsoidal body near the center of the organism. Its major and minor 

 axes are about 0.7 and 0.53 transdiameter in length respectively. The other cytoplasmic inclu- 

 sions are very sparse and include three brownish food masses and several minute spherules. The 

 surface of the body is covered with parallel longitudinal striae of granules linearly arranged, 

 about 13 across one face. Unfortunately the striae are not shown in our figure as converging 

 towards the apex as in Lohmann's original figure. The color of the body is light yellow. 



DiMF.xsioxs. — Lengtli, TOa* ; transdiameters, 26/* ; axes of micleus, 18m and 13/^. 



OccL'RREN"CE. — Figured by Loliniann (1908) from collections made in the 

 Baltic Sea off Kiel, Germany, in June. 



Discussion. — This species was originally described by Lohmann (1908) as 

 Cocldodhnum lougnm. His figure, however, does not show the characteristic 

 Cochlodinium arrangement of girdle, that is, with the torsion of the body giving 

 the girdle a length of at least 1.5 turns aroimd the bod}'. Neither is it possible 

 with the furrows as drawn to force a Cochlodinium interpretation of the species. 

 On the contrary, there seems to be a total lack of torsion with the girdle making 

 but one spiral turn around the body. His figure also seems to be inverted Avith 

 the girdle of the two faces drawn as though both parts were on the upper 

 surface. In the reproduction of his figure, given herewith in our text figure 

 DD, 10, these changes embodying our interpretation are incorporated, bringing 

 his figure into conformity with other species of Gtjrodininm. We therefore 

 l^lace Lohmann's species tentatively in the genus GyrodiniHm as GijrodinJum 

 louijam (Lohmann). 



It is quite possible that the drawing of this species is not inverted, and that 

 a Avhole tui'u or more of the girdle is omitted in Lohmann's drawing, in which 

 case the species is a Cochlodinium. Few, if any, Gi/rodinixni have the epicone 

 so pronouncedly larger than the hyi^ocoue as it is in G. lonfjuni as we orient 

 the body. 



Gyrodinium maculatum sp. nov. 



Plate 6, figure 62 ; text figure DD, 19 



Diagnosis. — A medium sized species w4th ellipsoidal ])ody, its length 1.49 

 transdiameters; sulcus extending from below the apex to antapex; girdle a 

 premedian, descending left .spiral, displaced 0.36 transdiameter; surface finely 

 striate ; violet pigment in epicone. Length, 61/*. Pacific off La Jolla, California, 

 July, August. 



