KOFOID AND SWEZY: UNAKMOREU DINOPLAGELLATA 453 



Pouclief), as intimated by Miss Lebour (1917&), since the ocellus is of the 

 diffuse ty])e in Profopsis n'ujra and of the simple or concentrated t,ype in Pou- 

 clutia pawn. The shape, size, and proportions of the l)ody are quite different 

 in the two and the girdle, as we have indicated above, appears to be of the 

 PoiicJietia type with torsion, rather than of the Gymnodiniiim type with none, 

 as in Protopsis. 



Pouchetia polyphemus (Pouchet) emend. 



Text figure 00, 11 



"Voisiu de Gymn [odinium] spirale Bergh et Archimedis Pouch." Pouchet (1885fl), pp. 



38-41. P&uchctia polyplumus scnsu latn. Indeterminable. 

 "Peridinium voisin de Gijmnndinium spirale," Pouchet (1885a), p. 85, pi. 2, figs. la-c. 



Three different forms figured, all Pouch cJia, but indeterminable. 

 Gymiwdinium pohiphcmus Pouchet (1885?)), pp. 529-531, pi. 26, fig. III. Fig. IV is a 



different and an indeterminate species of Pouchetia; (1886), pp. 223-224; (1887), pp. 



101, 112; (1894), p. 175. 

 Gymnodiniums polyphemus Pouchet (1885b), p. 529. Lapsus. 



Gymnodinium polyphemus Pouchet (1887), pi. 10, bottom. Lapsus. Plate contains figures 

 of Gymnodinium polyphemus var. roseum, pi. 10, fig. 1 {= Pouchetia roseum (Pouchet)) 



and Gymnodinium polyphemus var. nie/iion. pi. 10, figs. 2 A-B, 3, 4 (^Protopsis nigra 



(Pouchet). Figs. 2 C and 5 are indeterminable. 

 Gymnodinium polyphemus, Sehiitt (1895), pp. 94, 95. 



Diagnosis. — A large species with elongated, curved, ellipsoidal body, length 

 2.2 transdiameters ; girdle with about 1.75 turns, displaced about 0.5 total length 

 of body; sidcus with at least 2 turns, with apical and antapical loops; ocellus 

 pi'emediau, simjile, with elongated hemispherical lens and somewhat irregular 

 pigment mass, |)lasma colorless. Length, 104m. Atlantic, Concarneau, France ; 

 Dyref jord, Iceland, July and August. 



Description. — From our current knowledge of this genus, together with the indications of 

 girdle and sulcus in Pouchet 's figure, we are able to complete tentatively the structural features 

 sufficiently to obtain a faii'ly diagnostic account of this species. This interpretation is re])re- 

 sented in tlie modified figure (text fig. 00, 11) based on Pouchet's (18856, pi. 26, fig. 3), in 

 which we have interpreted his partially drawn sulcus and girdle as beneath instead of on tlie 

 upper side of the figure as he has drawn them. As is frequently the case in Pouchet's plates, 

 this figure has its posterior end uppermost on the plate. 



The body is elongated, ellipsoidal, flattened ventrally, broadly convex dorsally, the dorsal 

 side forming an arc with a radius of 1.5 transdiameters. The length is 2.2 transdiameters at 

 the voidest part which is a little anterior to tlie middle. The epicone and liypocone are subequal. 

 The apex is an asymmetrically flattened hemispliere, with the antapex contracted and deeply cleft 

 by the .suleal indentation witli pointed pi'olongalions on eitlier side. 



The ginlle begins at the right and anterior to the ocellus, about 0.5 transdiameter from Ihe 

 ajK'x, makes about 1.75 turns in a unifoi-udy descending left spiral, joining the sulcus again 

 posteriorly somewhere lU'ar 0.5 ti-ansdiameter from the antapex. There is a total infereingular 

 displacement of a lillle moiv than one transdiameter. The figure was evidently made from a 

 moribund individual and the furi'ow is scarcely impressed, except anieriorly. The sulcus evi- 

 dently has well defined anterior and posterior loops beyond the iutercingular region. The 



