KOFOID AND SWEZY: UNAKMORED DINOFLAGELLATA 469 



The nucleus is large, elongated ellipsoidal, with no visihle chromatin threads. It is located 

 near the central part of the body, its major axis nearly parallel to the major axis of the body. 

 Its major and minor axes are 0.88 and 0.40 trausdiamcter in length respectively. 



The protoplasm is finely granular with no food inclusions or oil globules in the specimen 

 figured. No pusules were noted. The color when first observed was rose pink diffused through 

 the protoplasm. After some mimites under the cover glass the color collected in small globules, 

 as figured in plate 6, figure 66, leaving the surrounding protoplasm with a yellowish tinge. No 

 surface markings or striae were detected. Both individuals were enclosed in a thin, hyaline cyst 

 when first observed. 



Dimensions. — Length, 101/'; trauscliameter, 63/^: axes of nucleus, 50/* and 

 28/*. 



OccFRRENCE. — Two individuals were taken July 7, 1904, with a No. 20 silk 

 net in a haul from 82 meters to the surface, 11 miles southwest of Point Loma, 

 California. Surface temperatures in July in this region range from 19° C to 

 21° C. 



Activities. — The flagella continued to be active within the cyst during ob- 

 servation. Shortly before cytolysis the animal began to rotate very rapidly 

 within the cyst and then its diffuse, rosy pigment collected in globules regularly 

 distributed in the peripheral plasma. 



CoMPARisoxs. — This is a member of the subgenus PoucJietiella with inte- 

 grated ocellus, but the integration is not complete, since there is still an amoe- 

 Iwid network of pigment. This is, however, slight in total amount, although 

 of wide extent, and does not seem to detract from the structural and functional 

 efficiency of the ocellus. The ocellus is of the elongated type with concentric 

 laminations. Other elongated lenses as in P. purpurdta. P. schuetti, and P. 

 maculata are transversely segmented. 



This is the largest of the species of Ponchctia with posterior ocellus, and 

 shares with others of that group the slight development of the antapical loop 

 of the sulcus. The large size, integrated ocellus, large apical loop and high 

 coloration are all indicative of the high specialization of this species. 



Pouchetia violescens sp. nov. 



Plate 11, figures 118, 120; text figure 00, 1 



Diagnosis. — A large species; body ovoidal, length 1.8 transdiameters ; girdle 

 a descending left spiral of 1.5 turns, displaced 0.66 transdiameters; sulcus with 

 ajDical and antapical loops with torsion of 3 turns ; ocellus of concentrated lens 

 and black pigment with lighter core; color, violet. Length, 115/*. Pacific off 

 La Jolla, California, June, July. 



Description. — This is a large species with stout, ovoidal botly, with its widest transdiameter 

 at the proximal base of the epicone somewhat anterior to the middle of the body. The epicone 

 greatly exceeds the hypocone in both length and volume. The epicone is long and domelike 

 with rounded apex notched by the anterior loop of tlie sulcus. Its length above the anterior 

 flagellar pore is 0.4 and from its distal end is 0.8 of the total length of the body. Below the 

 anterior pore it nari'ows down to a point in 1.5 turns. The hypocone is narrower than the 

 epicone and has the shape of a truncated cone of about 75°. It is deeply excavated in the region 

 of the lens, and its antapex is obliquely truncated. 



