KOPOID AND SWEZY: UNARMORED DINOPLAGELLATA 185 



overlianging borders. Tlio anterior flagellar pore opens at its junction with the sulcus, the pos- 

 terior pore about 1.5 widths of the girdle posterior to the anterior one. The transverse flagelluni 

 traverses about 0.3 of the length of the girdle. 



The sulcus extends from the girdle to the antapex as a wide, rather deep trough, which widens 

 at both ends. In some individuals the distal extremity notches the antapex. 



The nucleus is ellipsoidal and anteriorly placed. Chromatin strands could not be detected 

 in its structure. Its major and minor axes are about 0.5 and O.IM transdiameter in length 

 respectively. 



A saeklike, bright coral-red pusule opens into each flagellar pore. The cytoplasm is clear 

 and colorless. JMinute refractive bodies are numerous in the epicone and absent in the hypocone, 

 in which part a single large amyloid, or food body, is present. In both hypocone and epicone 

 are a few flat, ellipsoidal, orange green chromatophores, comparatively large, and located in the 

 perijihery. A distinct, double-contoured pellicle surrounds the body. Nutrition is probabl.y 

 holophytic. 



Di:n[ensions. — Length, 28/*; transdiameter, 26f; dorsoventral diameter, 10f>-; 

 major and minor axes of micleus, 14^* and 19/* respectively. 



Occurrence. — The individual figured was taken from the beach sand at La 

 Jolla, California, July 3, 1917. Others Avere present in the same material and 

 in the material examined at a later date. One individual Avas taken August 13, 

 0.75 of a mile oft" La Jolla, in a hatd made from 80 meters to the surface. 



This form was associated with Am phidinium dentatmn, A. eorpulentum, and 

 A. scissum, all typical beach forms. It presents tw^o of the characteristics of 

 these species in its dorsoventrally flattened body and chromatophores. 



CojNIParisons. — This species resembles G. hamulus in the possession of a 

 sinistral apical point, but differs from it in its larger size, and absence of striae. 

 The point is suggestive of the extension of the sulcits to the apex. 



Gymnodinium amphora sp. nov. 



Plate 3, figure 26 ; text figure AA, 6 



Diagnosis. — A large species with stout oA'oidal Ijody, its length 1.58 trans- 

 diameters ; girdle premedian, displaced nearly twice its ovm width ; sulcus ex- 

 tending from apex to antapex; color green yellow. Length, lal/". Pacific off 

 La Jolla, California, August. 



Description. — The body is large, ovoidal, nearly circular in cross-section, widest anteriorly 

 at the girdle and tapering posteriorly, with broad apices, its length 1.58 transdiameters at the 

 widest part. The hypocone greatly exceeds the epicone in size, being 0.45 of its own length 

 longer than the epicone. The epicone forms an asymmetrical, broad, rounded, caii-shaped ]iart 

 of the body with a length on the left and right sides of 0.33 and 0.36 of the total length of the 

 body respectively. It forms a cone of nearly 90°. The apex is broad and wndely notched near 

 the end of the sulcus. The hypocone is more symmetrical than the epicone, elongate, rounded 

 conical (30°), with the antapex much narrower than the apex, but without sulcal notch. 



The girdle is premedian in position and passes around the body in a slightly descending left 

 spiral direction, with a dis])lacement of about twice its own width. The furrow is wide, about 

 0.05 transdiameter, and deeply imbedded with overhanging, slightly undercut borders. The 

 proximal and the distal ends join the sulcus at distances from the apex of respectively about 



