118 MEMOIRS OP THE UNIVERSITY OP CALIPORNIA 



0. manna, Saville-Kent (1880-82), pp. 427, 428, pi. 24, figs. 53, 61. 



0. marina, Gruber (184), p. 417. 



0. marina, Blochmann (1884), pp. 46-49, pi. 2, figs. 14-21. 



0. marina, Biitschli (1885a), p. 845, pi. 45, fig. 12; (18856), pp. 558, 559, figs. 1, 2. 



0. marina, Stepaaoff (1885). 



0. manna, Gourret and Roeser (1886), pp. 448, 522-524, pi. 34, figs. 11-19. 



O. marina, Delage and Herouard (1896), pp. 306, 314, 336, fig. 533. 



0. marina, Entz (1897), pp. 177, 181; (1901), pp. 96, 98. 



0. marina, Senn (1900), p. 137, fig. 93; (1909), pp. 85-87; (1911), pp. 605-672, pi. 30, 



text figs. 1-7. 

 0. tnarina, Scherffel (1900), p. 3. 

 0. marina, Massart (1901), p. 81. 



0. marina, Lang (1901), p. 171; (1913), p. 231, fig. 232. 

 0. marina. Keysselitz (1908), pp. 334-339, pi. 19. 

 0. [marina], Willey and Hicksou (1909), p. 184, fig. 102. 

 0. marina, Giinther (1911), p. 9. 

 0. marina, Doflein (1911), p. 529. 

 0. marina, Minchin (1912), p. 278, fig. 123. 

 0. marina, Griessmann (1913), pp. 3, 14. 

 0. marina, Lebour (ima), p. 154; (1917b), pp. 198, 199. 



Diagnosis. — Body elongate oval, asAanmetrieal posteriorly ; girdle imperfect 

 on right side, without a postmargin; flagella midventral; stout tentacle-like 

 lobe pendant between the two flagella, dividing the broad luideveloped ventral 

 sulcus; colorless; length, 10-37;^. Marine. 



Description. — The body is elongate oval, widest at the girdle, its length 2.25 transdiameters, 

 and 2.6-3.2 dorsoventral diameter. The epieone is ovoidal, apex broadly rounded, over twice 

 the size of the hypocone ; its length at the origin of the transverse flagellum is about 0.5 total 

 length, and at the left margin of the body about 0.75 total length. The hypocone is about 0.5-0.7 

 the diameter of the epieone and 0.5-0.25 the total length in length, tapering conical, displaced 

 to the left, deficient on the right. It is broadly and deeply excavated ventrally. The antapex 

 is bluntly rounded. 



The girdle is peculiarly modified. It is incomplete, making about 0.75 of a circuit, fading 

 out on the right side of the body. The anterior lip is a sharply overhanging shelf, but the 

 posterior is lacking. Beginning in the midventral region, at the proximal end of the transverse 

 flagellum the girdle drops obliquely posteriorly to the left margin of the body about half way 

 to the antapex and continues thence transversely across the dorsal surface to the right side, where 

 it vanishes. The sulcus is a broad excavation spreading over a considerable part of tlie ventral 

 surface of the hypocone. It is divided in the median line by the pendant, tentacle-like lobe which 

 separates two flagellar pores. This lobe is pear-shaped in outline, is half as long as the hypocone, 

 and is attached bj- its stem between the two flagella to the anterior lip of the girdle and by its 

 dorsal face to the hypocone. It may be extended as a more slender tentacle. It does not appear 

 to be a modified flagellum. 



The longitudinal flagellum originates on the right side of this lobe and the transverse one on 

 the left. The former may extend directly posteriorly or it may wrap itself around the lobe, 

 turning first anteriorlj' to the pore of the transverse flagellum and projecting posteriorly from 

 that region, according to Senn (1911). There is a blepharoplast at the base of each flagellum. 

 The transverse flagellum is about as long as the girdle, and is thro\\Ti into short undulations or a 

 close spiral coil, but is not figured as a ribbon by Senn (1911), in which form it occurs in other 

 dinoflagellates. 



