KOPOID AND SWEZY: UNARMORED DINOPLAGELLATA 271 



Description. — The body is stout, ovoidal, its longest diameter posteqiiatorial in the upper 

 hypocone. its lengtli 1.33 tran.sdianieters at the widest part. The epieoue exceeds the hypoeone 

 by about 0.28 of its own lengtli. It is slightly asymmetrical, subconical (85°) towards the apex 

 and rounded posteriorly. Its lengtli above the girdle is about 0.56 of the total length of the body. 

 The hypocone has a length of about 0.4 of the total length. It is somewhat broader than the 

 epicone, witli rounded sides and deeply excavated at the antapex by the distal end of the sulcus. 



The exact outlines of the girdle are not shown in Pouchet's (1894) figure which shows a deep 

 constriction in the region of tlie girdle. It appears to be without displacement and is slightlj' 

 postequatorial in position. The furrow is about 0.1 transdianieter in width, deeply impressed 

 with rounded borders. The sulcus extends from the girdle to the antapex, where it forms a 

 deep, wide excavation that gives a bilobed appearance to the posterior portion of the body. The 

 position of the flagellar pores was not indicated. 



No internal structures are shown by Pouchet except a few small spherules near the peripher.y. 

 The surface is marked by projecting ridges, about 12 across the ventral face of the bod.y. These 

 seem to fade out near the apices. The color is green. 



Di:mensions. — Length, 80m; transdiameter, 60i". Poueliet (1894) gives its 

 dimensions as 80m by 75m. Tlie proi:)ortions of his figure, however, do not bear 

 out this measnrcnient of the transdiameter. We have taken the proportions of 

 his figure rather than distort it to conform to the proportions given in his text. 



OccLTREExcE. — Tliis forin was figured by Pouchet (1894) from the collections 

 made by the "La Manehe," from the Arctic Ocean near Spitzbergen, July 31, 

 3892, in a surface temperature of 2^6 C to 3-6 C. This is the only occurrence 

 on record. 



Cojmparisons. — This species is tentatively included in the suljgenus Pachtj- 

 (JiiiiiiiH because of the general resemblance of its striations to those of other 

 species included therein, such as G. puniceum sp. nov. (fig. Z, 5). The nearest 

 approach to the cingular constriction appears in G. coerulcnm Dogiel (fig. Z, 4). 

 This is one of the most northern species of Gi/i)niodi)iiuin thus far kno^^^l. 



Gymnodinium zachariasi Lemmermann 



Text figure BB, 3 



Gymnodinium paJustrc, Zaeharias (1899), pp. 142-144, figs. 1-9. 



G. zachariasi, Lemmermanu (1900), p. 116; (1902), p. 260; (1903), pp. 139, 146, 149. 



G. palustre, Wesenberg-Lund (1904), pj). 106, 107. 



G. palustre, Dogiel (1906), p. 31. 



G. zachariasi, West and West (1906), p. 92. 



G. zachanasi, Entz (1910), pp. 157, 158, 162, figs. 1-12 (questionable). 



G. palustre, Kolkwitz (1911), p. 346, pi. 6, fig. 2 (in ],art = G. palustre Sch.). 



G. palustre, Klebs (1912), p. 429. 



G. zachai-iasi, Schilling (1913), p. 16, fig. 12. 



G. palustre, Paure-Fremiet (1914), p. 41. 



G. zachariasi. West (1916), p. 53. 



Diagnosis. — A small species witli ovoidal body, its length 1.57 dorsoventral 

 diameters; girdle without displacement (?) ; sulcus (?) ; yellowish brown; ex- 

 trudes pseudopodia. Length, 44m. Fresh- water lakes near Plon, Germany; the 

 Irish lakes; Budapest, Hungary. 



