KOFOID AND SWEZY: UNAKMORED DINOPLAGELLATA 183 



Synoxy^iy. — Described ])y Sehmarda (1846) as Peridinium ndriaticum and 

 transferred by Diesing (1850) to his genus Hetermdncus and later (1886) to 

 Heteroaidax. 



In 1910 Broch described from the Adriatic a true thecate Peridinium which 

 he named adriaticum sp. nov. This name is preoccupied by Sclmiarda's (1846) 

 P. adriaticum. We therefore propose the name Peridinium hrochi nom. sp. nov. 

 for Broch 's species. 



Comparisons. — This species is close to G. fuscum (Ehrenberg, 1834), l)ut 

 differs from it as figured in smaller size, stouter body and rounded antapex, as 

 well as in being a marine instead of a fresh-water form. It is also rather near 

 G. marinum Saville-Kent (1880-82), but is less constricted and has a relatively 

 larger epicone. 



Gymnodinium aeruginosum Stein 



Text figure X, 25 



Grymnodim'um ar)-ugi)iosuni Stein (ISSS^i, pi. 2, figs. 19-22. 



G. aeruginosum, Biitschli (1885), p. 986. 



G. aeruginosum, Levander (1894(7), p. 43; (1894b), p. 210; (1901), p. 6. 



G. aeruginosum, Schilling (1891), p. 276, pi. 10, fig. 10; (1913), p. 19, fig. 18. 



G. aeruginosum, Schiitt (1895), pp. 9, 58. 



G. aeruginosum, Entz (1896), p. 22; (1902), p. 120; (1910), p. 157. 



G. aeruginosum, Butsehinsky (1897), p. 195. 



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



G. aeruginosum, Lemmennann (1899^ p. 126; (1900), p. 116; (1901), p. 358; (1902), p. 



260; (1905), p. 163; (1906\ p. 420: (1910), pp. 613-623, fig.s. 12-14. 

 G. aeruginosum, Schonichen and Kalberlali (1900), p. 231; (1909), p. 252. 

 G. aeruginosum, Amberg (1900), p. 83. 

 G. aeruginosum, Marsson (1901), p. 103. 

 G. aeruginosum, Ruttner (1906), pp. 9, 16. 

 G. aeruginosum., Paulsen (1908), p. 100, fig. 138. 

 G. aeruginosum, Lauterborn (1910), p. 452. 

 G. aeruginosum, Kolkwitz (1911), pp. 347, 371. 

 G. aeruginosum, Klebs (1912), p. 391. 

 G. aeruginosum, Zenker (1912), p. 27. 

 G. aeruginosum. West (1916), pp. 52, 75. 



DI.4GX0SIS. — A minute species with ellipsoidal, dorsoA-entrally flattened body, 

 its length 1.57 trausdiameters ; girdle slightly postmedian, without displace- 

 ment; sulcus extending from the middle of the epicone to the antapex; color 

 blue green. Length, 33m. Fresh water in Austria, Finland, Russia, Germany, 

 and Switzerland. 



Descru'Tion'. — The body is ellipsoidal, widest near the middle, with broad apices, its length 

 1.57 trausdiameters, its dorsoventral diameter 0.3 of its transdiameter. The epicone is slightly 

 larger than the hypocone, having a length 0.17 greater. It is broadly dome-shaped in ventral 

 view witli broad ai)ex. Its length is 0.5 of the total length of the body. Its sides are rounded 

 and the antapex is truncate or excavated by the sulcal notch. 



