192 MEMOIRS OF THE UNIVERSITY OP CALIFORNIA 



organism was enclosed in a crescent-shaped double-contoured cyst much more arcuate than that 

 of G. lunula and longer from tip to tip. Both flagella were active while under observation, 

 producing a slight rotation of the body in the cyst. 



DiMENSioxs. — Length, 63/^ ; dorsoventral diameter, 22^ ; axes of nucleus, 19m 

 and Sfj- ; length of cyst, 105m. 



OccuRRExcE. — This was taken in a sttrface haul at the end of the pier at the 

 Biological Station at La Jolla, California, July 19, 1917. 



Comparisons. — This species greatly resembles an individual shown in 

 Dogiel's (1906) figure 20, plate 1, which he includes in Gym/nodinium lunula. 

 The shape of the body is slightly different in the two forms included by Dogiel, 

 the one referable to G. hi conic having a greater convexity of the dorsal and 

 concavity of the ventral surfaces. The differences are probably adequate for 

 specific distinction. Both Dogiel's figure 20 and our individual differ widely 

 from G. hi H Ilia, in size and slia^je of the body as well as in their relative pro- 

 portions. The shape of the enclosing cyst is apparently the only ground for 

 its inclusion by Dogiel with those of G. honila, and e\cn this shows distin- 

 guishing characteristics. 



Gymnodinium bif urcatum sp. nov. 



Text figures AA, 2, 3 



Diagnosis. — A large species with a pecitliarly laterally flattened body, 

 l)roadly ovoidal in side view, double funnel-shaped in ventral view, its length 

 1.07 dorsoventral diameters; hypocone dorsoventrally deeph' bifurcate by the 

 sulcus; girdle submedian, displaced one width; sulcus short and very deep on 

 hypocone ; color, pinkish grey. Length, 125m. Pacific off La Jolla, California, 

 August. 



Description. — The body is broadly ovoidal in lateral view, widest anteriorly in the posterior 

 epieone, strongly laterally compressed, especially on each side of the girdle region. Its length 

 is 1.07 dorsoventral diameters at the widest part. Its transdiameter through the girdle region 

 is about 0.56, through the midpart of the epieone about 0.12, and of the hypocone 0.15 of the 

 dorsoventral diameter. The epieone and hypocone are subequal in length, but its broader dorso- 

 ventral diameter gives to the epieone a somewhat greater size. The epieone is subsemicireular 

 in outline viewed laterally, with a very slight asymmetry on the ventral side. In ventral view 

 it is inverted funnel-shaped, flariug widely in the posterior third of its length. Its length on 

 the left and right sides is about 0.5-3 and 0.50 respectively of the total length of the body. The 

 apex is smoothly rounded. The hypocone has the shape of a broad, rounded cone of about 70° 

 in lateral view, with broad, rounded antapex. In ventral view it is bifurcate funnel-shaped, 

 the cleft formed by the sulcus extending nearly its entire length to within a girdle's width of 

 the girdle itself. 



The girdle is submedian, the distance of its proximal and distal euds from the apex being 

 0.53 and 0.50 respectively of the total length of the body. It passes around the body with only 

 a slight posterior deviation from a transverse direction in the distal fourth of its course, with 

 a displacement of about its own width. The furrow i.s wide, about O.O-i transdiameter in width. 

 and deeply impressed with smooth borders, of which the anterior one is prolonged into a thin, 



