KOFOID AND SWEZY: UNARMORED DINOPLAGELLATA 205 



Gymnodinium dogieli .s]). uov. 



Plate 3, figure 34; text figures AA, 1, 8 



Diagnosis. — A large species with bieonical body, its length 2.03 transdiam- 

 eters : epicone concave ; submedian girdle, displaced nearly its own width ; sulcus 

 extending from a short distance above the girdle to the antapex; differentiated 

 ectoplasm; coloi- orange yellow. Length, 193^^. Pacific off La Jolla, California, 

 July, August. 



Description. — The body is nearly bieonical, slender eaiiipanulate anteriorly, wide posteriorl.y, 

 with narrowly rounded apiees, its length 2.03 transdiameters at the widest part. The epicene 

 exceeds the hypoeone in length by about 0.3 of its length, but being much narrower is less in 

 volume. It forms a long, slender cone, the sides of which form an angle of about 18° with the 

 longitudinal axis of the body anteriorly and in the posterior third an angle of about 43°. The 

 sides are thus concave and symmetrical with narrowly rounded apex. Its length is about 0.56 

 of the total length of the body. The hypoeone forms a broader cone, its sides forming an angle 

 of about 35° with the longitudinal axis. At the girdle they flare out into a wide, shelflike 

 extension to serve as its anterior border. The sides are symmetrically rounded with a broadly 

 rounded antapex without sulcal notch. 



The girdle is protuberant, located slightly posterior to the middle of the body, its distance 

 from the apex being about 0.56 of the total length of the body on the right, slightly less on the 

 left side. Its distal end is displaced posteriorly somewhat less than its own width. The furrow 

 is wide, about 0.06 transdiameter, and is deeply impressed with widely overhanging borders, 

 the proximal border cut under by the furrow, the distal gradually rounded. The sulcus invades 

 the epicone for a vei-y short distance only as a rather shallow furrow. Beyond the girdle it 

 extends as a shallow trough in an almost straight line to the antapex, expanding slightly 

 posteriorly, until at the antapical region its borders spread out to meet the posterior borders 

 of the body on each side of the antapex. The anterior flagellar pore opens at the proximal 

 junction of the girdle and sulcus, the posterior flagellar pore at about 0.3 of the distance from 

 girdle to antapex. 



The nucleus is a large ellipsoidal body in the posterior part of the hypoeone. Its major and 

 minor axes are about 0.4 and 0.27 transdiameter in length respectively. 



A small, spherical pusule opens into the posterior flagellar pore through a long, slender canal. 

 The cytoplasm is finely granular and is usually filled with various cell inclusions. In the 

 central region near the anterior pore was a large group of small, highly refractive, double- 

 contoured, dark greenish granules. Mingled with these were a number of yellowish spheroidal 

 bodies, probably food masses. Above these and almost filling the epicone were large vacuoles 

 of a faint bluish color, presumably of a fatty nature. At the apex were a smaller group of the 

 same refractive spherules found in the central part of the body, with a group of radial, greenish 

 rodlets. A second group of rodlets was found just above the girdle region and a third group 

 of longer rodlets radiating out from the spherical part of the pusule. Partly filling the hypoeone; 

 and reaching upward into the epicone were large vacuoles filled with a pink fluid like that found 

 in the pusule. 



The protoplasm is divided into distinct ectoplasm and endoplasin. The ectoplasm is about 

 4n in thickness in the hypoeone and slightly less in the epicone. It is composed of a thin, double- 

 contoured layer, bright yellow in color, surmounted peri{)herally by an alveolar layer. The 

 alveoli are rounded outwardly, giving to the outline of the body an uneven, wavy line. This 

 layer is deep orange at the antapical region, shading to a lighter tone anteriorly. The color of 

 the endoplasin is a greenish yellow with bluish tinges. The combination of colors in this species 

 gives a rich Oriental efl"ect, impossible adequately to describe or to reproduce with water colors. 



