136 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



Description. — Body broadly oval, rounded posteriorly and pointed anteriorly, its length 1.59 

 transdiameters at the widest part. The epieone is a minute caplike portion having a length of 

 0.16 of the total length of the body. It is conical in shape (90°) with a sharply pointed apex. 

 The hypocone is rotund ovoidal with broad rounded antapex, widest about its middle, and in 

 length 0.67 of the total length. 



Lolimann's (1908, 1911) figures are both apparently dorsal views which show the girdle 

 passing transversely across the body and give no indication of the sulcus. The girdle is wide, 

 0.17 trausdiameter, and rather deeply impressed. Its distance from the apex is about 0.16 of the 

 total length of the body. 



The nucleus is a small ellipsoidal body lying near the antapex. Its major and minor axes 

 are about 0.4 and 0.3 transdiameters, respectively. The central part of the cytoplasm is usually 

 occupied by a large, yellow brown body, probably a food body. The remainder of the ej'toplasm 

 contains numerous minute spherules. 



DiaiEXSioxs. — Length, 27/^; transdianieter, 17/*; axes of nucleus, 7 and 5/^. 



OccrERExcE. — Figured by Lolnnann (1908, 1911), front the Baltic Sea off 

 Kiel, Germany. He records it as being present thronghout most of the year. 

 The only other record of its occurrence is that of Lebour (1917?;) from Ply- 

 mouth Sound, England. 



Amphidinium cucurbita sp. nor. 



Plate 1, figure 9 ; text fibres U, 12, W, 3 



Diagnosis. — A large species with rotund ellipsoidal body, its length 1.46 

 transdiameters, girdle far anterior with no displacement ; sulcus extends from 

 girdle to antapex; surface Avith both striae and furrows; color yellow. Length, 

 110/'. Pacific off La Jolla, California, June to August. 



Description. — The body is rotund ellipsoidal, with broad apices, its length 1.46 transdiam- 

 eters at the widest part. The epieone occupies only a minute portion of the body, its length on 

 the dorsal and lateral sides being about 0.07 of the total length of the body. It extends posteriorly 

 on the ventral side for a length of 0.36 of the total length, forming a triangular portion of about 

 55°. Its greatest width is 0.56 of the trausdiameter of the hypocone. In ventral view it thus 

 forms the sector of a hemisphere. The hypocone has a length on the dorsal and lateral faces of 

 the bo3y of 0.9 of the total length of the body. Its sides are subparallel for the middle third of 

 their length, the posterior third being hemispherical and the anterior sloping to the girdle. Both 

 the apex and antapex are broadly rounded, almost flattened, the latter being sometimes slightly 

 indented by the sulcal notch. 



The girdle is placed far anteriorly, its distance from the apex on the dorsal and lateral sides 

 being about 0.07 of the total length of the body. Yeutrally both ends of the girdle turn abruptly 

 posteriorly to meet the girdle at a distance of 0.36 of the total length of the body from the apex. 

 The ends are \rithout displacement. The furrow is narrow and deeply imbedded with sharp- 

 angled borders. The sulcus extends from the girdle to the antapex as a deep, narrow trough, the 

 sides of which become widely deflected near the posterior end of the body. Its depth also 

 increases posteriorly, until it has a depth of nearly 0.5 of the dorsoventral diameter of the body. 

 Its sides are smoothly rounded and in front of the posterior pore may overlap sufficiently to 

 obscure the furrow. The anterior flagellar pore opens at the junction of the girdle and sulcus 

 and the posterior pore a short distance from the antapex. 



The nucleus is reniform in shape and is located in the posterior portion of the bod.y. Its 

 chromatin structure could not be analyzed. Its major and minor axes are 0.45 and 0.26 trans- 

 diameters respectively. 



