304 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



DiMExsioxs. — Lengtli, 102-118^; transdiameter, 58-68/^; axis of nucleus, 25/^. 



Occi'RREXCE. — Two individuals were taken August 21, 19T7, with a No. 25 

 silk net, 5 miles off La Jolla, California, in a haul from 63 meters to the surface 

 and in a surface temperature of 21-9 C. 



CoMPAKisoxs. — In the outline of the body and the arrangement of girdle 

 and sulcus this species resemliles G. truncus sp. nov. (fig. DD. i). Its lack of 

 surface striae, however, differentiates it from that species and places it in the 

 subgenus LaevigeUa. It is also different in its relatively shorter intercingular 

 sulcus and its differentiated apical point. It is the most rotvmd representative 

 in the subgenus Gyrodinmm. 



Gyrodinium foliaceum nom. sp. nov. 

 Text figure CC, 18 

 Gymnodinium viride Schiitt (1895), pi. 26, fig. 88. 



DiAGXosis. — A small species with rotimd ellipsoidal body, its length 1.2 

 transdiameters ; girdle a descending left spiral, displaced 0.3 transdiameter; 

 sulcus extending f I'om girdle to antapex ; green chromatophores. Length, SOa^. 

 Atlantic or Bay of Naples. 



Desckiption. — The body is stout ellipsoidal, broadly rounded at both ends, its length 1.2 

 transdiameters at the widest part. The hypoeone exceeds the epicone in length by about 0.15 

 of its own length. The epicone is subhemispherical with broad apex or the apex may be marked 

 off by a slight pointed projection. It has a length on the left and right sides of about 0.18 and 

 0.54 respectively of the total length of the body. The hypoeone is broad and rounded, somewhat 

 less s3Tnmetrical than the epicone, and without suleal notch. 



The girdle joins the sulcus proximally about 0.18 of the total length of the body from the 

 apex. It sweeps around the body in a descending left spiral course which becomes displaced 

 posteriorly 0.3 transdiameter. The furrow is wide, 0.09 transdiameter, and deeply impressed with 

 overhanging borders. The flagella and pores were not indicated by Schiitt (1895). The sulcus 

 begins at the girdle or it may arise at the apex. It extends posteriorly to the antapex in a 

 sinuous line, but with no resulting torsion. 



The nucleus is an ellipsoidal body in the posterior part. Its major and minor axes are 0.4 

 and 0.26 transdiameter in length respectively. A small sacklike pusule is present in the anterior 

 part of the body connected with the region of the anterior pore by a slender canal. A few large, 

 clear vacuoles are usually found in the cytoplasm, particularly in the epicone. Large, irregularly 

 shaped, leaflike green chromatophores are found, sometimes near the middle of the body, in other 

 cases filling the peripheral zone over the entire body. 



DiMEXSioxs.- — Length, 50/^; transdiameter, 42/*; axes of nucleus, 17/* and 11/*. 



OccuEREXCE. — Figured by Schiitt (1895) from collections made l)y the 

 Plankton Expedition, presumably from the Atlantic or from the Bay of Naples. 



Syxoxymy. — Tliis form was described by Schiitt (1895) as Gfimnodinium 

 viride sp. nov. without knowing that this name had been used previously by 

 Penard (1891) for a different species from fresh water. We therefore propose 

 the new name foUacetim for it, and, liy reason of its girdle, transfer it to the 

 genus Gyrodinium. 



