142 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



epieone lias the shape of a broad, flat cone of about 105° with blunt apex. Its length is about 

 0.22 of the total length of the body, except for a slender point extending posteriorly on the right 

 side of the sulcus with a length of 0.45 of the total length. The hypocone is long, with a length 

 of 0.73 of the total length of the botly. Its sides are subparallel for about 0.7 of their extent, 

 flaring slightly around the girdle and rounded posteriorly to the broad, symmetrical antapex. 



The girdle encircles the body near the anterior end. Its proximal end joins the sulcus at a 

 distance from the apex of 0.22 of the total length of the body. It passes around the body trans- 

 versely for about 0.8 of a turn, when it is abruptly deflected posteriorly, with a displacement of 

 0.44 transdiameter, meeting the sulcus at an angle of about 45°. The furrow is about 0.12 trans- 

 diameter in width, and deeply impressed. The sulcus begins a short distance from the apex and 

 extends posteriorly to the antapex in a slightly sinuous course. The trough is shallow anteriorly, 

 deepening posteriorly with a wide flare of the borders in the autapical region. The anterior 

 flagellar pore is found at the proximal junction of the girdle and sulcus, the posterior pore about 

 midway between the distal junction and the antapex. 



The nucleus is a relatively large, spheroidal bo<^ly in the posterior half of the hypocone. It is 

 filled with fine beaded chromatin strands. Its axis is 0.52 transdiameter. 



A small sacklike pusule opens into each flagellar pore. The cytopla-sm is granular and alveolar 

 in structure, with relatively coarse alveoli. This is omitted in the figures for the sake of clearness. 

 The color of the cytoplasm is pearl grey. In the peripheral laj'er are numerous blue green oil 

 droplets and leaflike, bright green yellow chromatophores. These are placed closely together 

 through the entire peripheral layer of the cytoplasm. The surface of the body is marked by 

 longitudinal grooves, about twelve in number, across one face. On the epieone these are radially 

 arranged around the apex and die out before reaching the girdle. On the hypocone they are 

 subparallel, fading out before reaching the girdle and the antapex. 



Dimensions. — Length, 48-67/^; transdiameter, 25-32m; diameter of nucleus, 

 14/*. 



OcciTKRENCE. — The first individual was taken July 20, with a No. 25 silk net, 

 6 miles oi¥ La Jolla, California, in a haul from 80 meters to the surface and in 

 a surface temperature of 21° C. A second one was taken July 24, 2.75 miles oH 

 Ija Jolla, in a haul 80 meters to the surface and in a surface temperature of 

 21?9C. 



Co:mparisoxs. — Like A. cucurhita this species stands near the border line 

 dividing Ampliidinium from Gymnodinium. The relatively minute size of the 

 ejjicone places it with the former genus rather than with the latter. 



Amphidinium globosum Schroder 



Text figure U, 20 



Amphidinium glohosum Schroder (1911), pp. 616, 651, fig. 16. 

 A. glohosum, Schiller (1912), p. 493. 



Synonymy. — This form was figured by Schroder (1911) from the Adriatic 

 Sea near Rovigno, Austria. It is almost globular in form with minute brown 

 chromatoiihores, the length of the h}^50Cone being only twice that of the epieone. 

 The relation of epieone and h^^pocone is not the characteristic one of the genus 

 Ampliidinium, and is sufficient to make its inclusion with that genus doubtful. 

 The data given are too slight to place it with any degree of certainty, at least 

 until its characteristics have been more fully analyzed. 



