KOFOID AND SWEZY: UNAEMORED DINOFLAGELLATA 357 



body. The epicone has a length on the left of 0.23 and on the right of the sulcus of 0.87 of the 

 total length of the body. It is in lateral view a conoid of 35° with hemispherical apex. The 

 greatest length of the hypocone is 0.77 of the total length of the body, while at the right of the 

 sulcus its length is only 0.13 of the total length. The antapical region is markedly asymmetrical, 

 the right side projecting as a hemispherical lobe 0.5 transdiameter in diameter. 



The girdle joins the proximal end of the .sulcus 0.23 of the total length of the body from the 

 apex. It sweeps around the body in a descending left spiral course. In the proximal 0.5 turn 

 it is deflected posteriorly only about 15°, but in the next 0.5 it turns posteriorly in a sigmoid 

 curve deflected 45° to 60°, until it reaches a point 0.03 of the total length of the body from the 

 antapex, where it slackens again to 25° for a short distance and joins the distal end of the sulcus. 

 It is relatively wide, 0.14 transdiameter, and is deeply impressed with smooth overhanging 

 borders. The anterior flagellar pore opens at the anterior junction of the girdle and sulcus, the 

 posterior pore, 0.5 transdiameter above their distal junction. 



The sulcus invades the epicone as a longitudinal groove which terminates near the apex. As 

 a descending left spiral it makes 0.5 turn before meeting the distal end of the girdle 0.13 of the 

 total length of the body from the antapex, where it forms a deep, wide excavation on the face 

 of the hypocone. It is a narrow, rather shallow groove with smooth borders lying in the venti-al 

 spiral depression. Its total intercingular displacement is 0.64 of the total length of the body. 



The nucleus is ellipsoidal and located slightly above the center of the body. Chromatin 

 threads could not be detected in its contents. Its major and minor axes are 0.69 and 0.36 

 transdiameter in length respectively. 



A long sacklike pusule opens distally into each flagellar pore. The cytoplasm is finely 

 granular. There are a few blue-green refractive spherical oil drops scattered through it, and a 

 large food mass in the center. There were no striations or other markings on the surface. The 

 color of the organism is oil yellow shading to yellow ochre at the apices, with pearl grey massed 

 in the center. A thin-walled, symmetrically elliptical, hyaline cyst enclosed the organism. This 

 was surrounded by a second cyst, slightly larger than the inner one, of the same general appear- 

 ance and structure. There were no chromatophores and nutrition is evidently holozoic. 



Dimensions. — Leugtli, 65/^ ; transdiameter, 27m ; axes of micleus, 23/^ and 12f ; 

 axes of outer cyst, 80/* and 57/* ; of inner, 70/* and 45/*. 



OccuREENCE. — A single individual was taken July 24, 1917, with a No. 25 

 net, in a haul 2.75 miles off I^a Jolla, California, from 80 meters to the surface 

 in a surface temperature of 21-9 C. 



AcTrnxiES.- — These were limited to rotation within the cyst. 



Comparisons. — This species is a memlier of the C. distortmn group and is 

 next to C. distortum (fig. HH, 9) in the degree of ventral excavation and torsion 

 of the body. It has, however, more of the usual Cochlodininm proportions. 

 Tlie asymmetry of the antapex allies it with the C. helix (fig. HH, 8). 



Cochlodinium cereum sp. nov. 



Text figure GG, 5 



Diagnosis. — A medimn sized species with elongated, ellipsoidal body, its 

 length 2 transdiameters ; girdle a descending left s])iral of 1.7 turns, displaced 

 0.94 transdiameter ; sulcus witli apical and antapical loops and a torsion of one 

 turn; color, yellow. Length, 76/*. Pacific off La Jolla, California, July. 



