KOFOID AND SWEZY: UNARMORED DINOPLAGELLATA 329 



A large, sackliko pusule opens into the anterior flagellar pore and another, slightly smaller, 

 into the posterior pore. The cytoplasm is finely granular and alveolate in structure and often 

 contains one or more food masses. The body sometimes contains numerous large vacuoles filled 

 with a fluid, colored pink like that in the pusules. Scattered profusely in its surface are minute 

 green circles which seen in side view are the ends of small, slender, blue-green rodlets or rhabdo- 

 somes, arranged at right angles to the surface in a peripheral zone. The color of the body is 

 amaranth purple condensed in a thin layer immediately beneath the periplast (pi. 8, fig. 91). 

 This same coloring matter is generally collected in a denser mass at the antapex. The color 

 may vary to something nearer a rosy tint as in figure 64, plate 6. The surface is striated with 

 broken lines showing an amaranth purple color. On the epicone the striae are about 2.5/n distant 

 from each other at the girdle and on the proximal part of the hypocone about half that width, 

 thus making the number on the hypocone nearly twice that on the epicone. There are about 

 20 across the ventral face on the epicone. 



Dimensions. — Length, 52-86/^; transdiameter, 30-45m; transdiameter of 

 nil (^] ens, 16-22/*. 



Occurrence. — This was first taken Jnly 9, 1901, with a No. 12 silk net, in 

 a surface haul, 7 miles off Point Loma, California. It was taken again July 18, 

 1917, with a No. 25 silk net, in a surface haul, 4 miles off La Jolla, California, 

 in a surface temperature of 20-2 C. It occttrred also on July 20 and 23 in hauls 

 made 6 miles off La Jolla from 20 and 80 meters to the surface respectively and 

 in surface temperatures of 21-5 C and 20?8 C. 



Comparisons. — This species, with its peripheral zone of rodlets, resembles 

 G. fis.sKiii (fig. DD, 8) and G. obtiisuni (fig. DD, 3). In its coloring of amaranth 

 pnr])le it is unlike any other species of Gijrodijiinw, its nearest approximation 

 being found in Pouchctia pio-purafa (pi. 8, fig. 87). The localization of the 

 color in the peripheral layer is similar to the condition in Pouchetia voracis 

 (pi. 8, fig. 89). As in many other species of the G}^nnodiniidae, the colored 

 pigment shows here also a strong tendency to collect at the apices. The local- 

 ization of the ])igmcnt in the antapex, the interrupted striae, and the size are 

 (|uite similar to these features in G. n(hricai(<hifi(ni sp. noA^ (fig. DD, 18), but 

 the more rotund body and the purple instead of red color differentiate the two. 



Gyrodinium pusillum (Schilling) 

 Text figure CC, 3 



Gymnodiniiim pusillum Schilling (1891a), p. 60, pi. 3, fig. 15; (18916), p. 201; Spiro- 



dinium pusillum. (1913), pp. 21-27, fig. 22. 

 G. pusillum, Mez (1898), p. 216. 



G. pusillum,, Schonichen and Kalberlah (1900), p. 231 ; (1909), p. 252. 

 G. pusillum. Massart (190n, p. 82. 

 G. pusillum. Ohno (1911), p. 91. 



Diagnosis. — A minute species with ol)li(|uely asymmetrical ellipsoidal body, 

 its length 1.5 transdiameters ; epicone obliquely slo])ed to the right; girdle a 

 descending left spiral, displaced about 0.?> transdiameter ; stilcus extending from 

 girdle to antapex; yellow chi-omatophores. Length, 2.3/*. Fresh-water swamps 

 near Basel, Switzerland. 



