250 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



CoMPARisoxs. — The marked biconical s^Tnmetry of the epicone and hypocone, 

 combined with the striate surface, distinguish this species, at once, from all 

 others in the gemis. It has some\Yhat the same size and proportions as G. 

 scopulosum sp. nov. (fig. X, 6), but is less rotund and has striae, or at least 

 linear marldngs, due to modifieations on or in the surface layer of cytoplasm. 



Gymnodinium roseolum (Schmarda) Stein 



Text figure BB, 11 



Glenodinium roseolum Schmai'da (1854), p. 12, pi. 1, fig. 9. 



G. roseolum, Leuekart (1861), p. 256. Based on Schmarda (1854). 



G. roseolum, Diesing (1866), p. 105. 



G. roseoluyn. Stein (1878), p. 73, as Gijmnodinium roseolum, p. 90. 



Gymnodinium roseolum, Ej-ferth (1879), p. 19. 



Peridinium roseolum, Maggi (1880a) ; Glevodinium roseolum (1880fc), p. 12. 



Gi/mnodinium. roseolum, Sa\'ille-Kent (1880-82), p. 444, pi. 25, fig. 53. Based on 



Schmarda (1854). 

 Glenodinium roseolum, Biitsehli (1885), pp. 965, 1018. 

 G. roseolum, Entz (1888)), p. 41: as Gymnodinium roseolum, (1902), p. 124; (1907). p. 



17; (1909), p. 253. 

 Gymnodinium roseolum, Schilling (1891b), pp. 199, 206. Lapsus. 

 Glenodinium roseolum. Sehewiakoff (1893), p. 157. 

 G. roseolum, Lemmermann (1900), p. 118. 



Diagnosis. — A minute species with oAoidal Ijody, its length 1.28 transdiam- 

 eters ; girdle premedian ; color pale pink. Fresh water in Egypt, February. 



Description. — The hody is ovoidal, widest near the middle, its length 1.28 transdiameters at 

 the widest part. The epicone is about 0.5 the length of the hypocone and 0.68 its greatest width, 

 with rounded outline. The hypocone is rounded anteriorly, subconical (about 63') posteriorly, 

 with blunt apex. 



The girdle is premedian in position, its distance from the apex being about 0.3 the total 

 length of the body. It is narrow and deeply impressed. The sulcus, flagella and nucleus were 

 not observed by Schmarda (1854), the only cell inclusions being one red and several green 

 spherules (chlamydomonads). The general color is pale pink. It is apparently holozoic in 

 nutrition. 



DiMExsioxs. — Length, 38/^; trausdiameter, 29.5/^. 



OcciTEREXCE. — It was figured by Sclnnarda (185-1) from the Natron Sea in 

 Egypt in February. 



Co:mparisoxs. — Schmarda 's description is rather inadequate, but since the 

 form figured is quite unlike any other species of Gjimnodinium it seems best 

 to let it stand until further woi*k shall complete the description. Its shape, 

 proportions, and size are near those of G. cinctum sp. nov. (fig. X, 28), a marine 

 species, but its color differs, being pink instead of ochraceous. The color is 

 unusual in fresh-water species. 



Synoxymy. — It was figured by Schmarda (1854) as Gloiodiniiiw rnxenhon^ 

 but it was later changed by Stein (1878) to Gymnodiniuhi. 



