216 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



Syxonymy. — Originally described by Bergli (1881&) as Gumnodininm 

 gracilc. It was referred, without explanation, to Spirodiuiion by Entz, Jr. 

 (1902, 1907, 1909), but the structure of the girdle, with little displacement and 

 no overhang, does not justify the transfer. It stands near Spirodinium, how- 

 ever. Bergh's form was slightly smaller than the forms present at La Jolla, 

 his measurements being 90m long and 24^^ wide. Pouchet (1883, 1885fO describes 

 two forms as G. graciJe Bergh which have no resemblance to each other and less 

 to Bergh 's figures (1881Z>). His earlier one (1883) shows a Gymnodinium with- 

 out striae and the girdle slightly posterior to the midregion of the body. His 

 second one (1885fO is a Gi/wdiuiiim with the girdle premedian and displaced 

 0.33 of the body. 



The form described l^y "Wriglit (1907) as G. gracile from the cold waters 

 off the shores of ISTova Scotia may be a doubtful member of this species. j\Iuch 

 more work on these forms will be required before we can say, definitely, that 

 these frail organisms can exist, as specifically identical individuals, in the warm 

 waters of the Mediterranean and off the coast of the southern part of California, 

 and in the cold waters of the Arctic current that bathes the eastern shores of 

 Canadian America. His form also lacks the striate surface characteristic of 

 G. gracilc. but this may have been omitted in the drawing. 



Comparisons. — This species belongs in the siibgenus Paclujdininm and finds 

 its nearest counterpart in G. abhrcviatum sp. nov. (fig. Z, 7), differing from it, 

 however, in its lack of a distinct alveolar layer. It is somewhat like G. anreum 

 sp. nov. (fig. Y, 3) in size and general proportions, but is of a duller color, more 

 rotund hypotheca, different cell contents, and different striations. 



Gymnodinium gracile var. exiguum Pouchet 



Text figure BB, 17 



G^ymnodinium gracilc var. rxiguum Pouchet (1883), p. 447, pis. 20, 21, fig. 40. 

 G. gracile var. exiguum. Lemmermann (1899), p. 358. 

 G. gracile var. exiguum, Paulsen (1908), p. 108. 



Description. — An organism with a rotund hody divided into two suhequal parts by the 

 girdle, slightly wider auteriorlj'. The complete course of the girdle and the sulcus are not 

 figured or described by Pouchet (1883). The nucleus is a small, spheroidal body near the 

 antapex. Near the nucleus is a large, irregular body of red pigment. The color of the organism 

 is pale rose. Its length is 30/i, its transdiameter 15;u. Abundant in the Atlantic off Concarueau, 

 France. 



Pouchet's (1883) description and figure do not afford sufficient data for 

 specific determination, or even generic status. The girdle on the dorsal side 

 might lie that of Gi/rodininm. Until it has l)een redescribed it must, therefore, 

 be placed among the species utccrtae scdis. 



