332 MEMOIRS OF THE UNIVERSITY OP CALIFORNIA 



Description. — The body is broadly ellipsoidal with broad apices, circular in cross-section, its 

 length 1.95 transdiaraeters at the widest part. The epieone and hypocone are subeqiial in size. 

 The epieone is elongate hemispherical in shape with broad, .symmetrically rounded apex. It 

 has a length on the left and right sides of tlie body of 0.42 and 0.67 respectively of the total 

 length of the body. The hypocone in Schiitt's figures presents a metabolic appearance poster- 

 iorly. This is probably due to the recent ejection of a food mass, as we have frequently observed 

 the same appearance in Gijmnodinium heterostriatum following the ejection of a food body when 

 first placed under a cover slip under the microscope. In a short time the thus modified posterior 

 part resumes its normal rounded appearance. 



The girdle is a descending left spiral with a distance from the apex at its proximal and distal 

 ends of 0.42 and 0.67 respectively of the total length of the body. The furrow has a width of 

 about 0.06 transdiameter, becoming narrower at its distal end, and is rather shallow, with smooth, 

 overhanging borders. Tlie sulcus extends from the apex to the antapex in a slightly sinuous line. 

 The transverse fiagellum arises at the proximal junction of the girdle and sulcus, the longitudinal 

 flagellum midway between the distal junction and the antapex. 



The nucleus is a large ellipsoidal body, filled with parallel moniliform chromatin strands, 

 and lying in the anteroeentral part of the body, oblique to the longitudinal axis. Its major and 

 minor axes are about 0.73 and 0.4S transdiameter in length respectively. The anterior end of 

 the body is filled with large alveoli. The surface of the body is closely beset with longitudinal, 

 beaded striae, nearly equal in number on both epieone and hypocone, about 30 across the ventral 

 face. Color (?). 



Dimensions. — Length, 117m ; transdiameter, 60/^ ; axes of nucleus, 4-t^ and 29^. 



Occurrence. — Figured by Schiitt (1895) presumably from material of the 

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



Synonymy. — This organism was described by Schiitt as Gi/nnwdiuhon 

 cornittum n. sp., a name ^yhich \Yas pi*eoccupied by Pouchet (1885(/) in his G. 

 cornutum {^Gyrodininm cornnfum (Pouchet) Kofoid and Swezy) ; it was 

 later changed by Lemmermann (1899) to S pirodinium schuetti. 



Comparisons. — The only other species of Gurodinhim with striae and a 

 rotund epieone are G. fruncus sp. noy., G. grave (Meunier), G. pingue (Schiitt), 

 G. ruacidatiim sp. noy., and G. postmacidatum sp. noy. (figs. DD, 4, 7, 15, 19, 20). 

 G. tiHucus is more rotund, with shorter epieone and fewer striae; G. grave is a 

 smaller species with much more displacement and torsion of girdle ; G. pingue 

 is a smaller species with more slender body and relatiyely greater displacement ; 

 G. 'niacidatum is much smaller, is pigmented, and has more iuterciugular 

 torsion; and G. postmacidatum has a pointed pigmented antapex. 



Gyrodinium spirals (Bergh) 



Plate 4, figure 43 ; text figure DD. 14 



Gymnodinium spirale Bergh (1881a), p. 66; (1881&), pp. 253-255, pi. 16, figs. 70, 71. 



G. spirale, Saville-Kent (1880-1882), p. 858. 



G. spirale, Pouchet (1883), pp. 446. 447; (1885a.), pp. 44, 67-69. pi. 4, fig. 30. 



G. spirale, Daday (1884), p. 13, fig. 4. 



G. spirale, Klebs (1884), p. 730; (1912), pp. 429, 430. 



Spirodinium spirale, Entz, Sr. (1884), p. 39; Entz, Jr. (1902a), p. 92; (1902&), p. 119; 



(1905), p. 108; (1907), pp. 17, 24; (1909), pp. 254. 255. 

 Gymnodinium spirale, Biitschli (1885), pp. 965, 974, 975, 993, 1017, 1018, pi. 51, fig. 5. 



