582 



figures of both species; but the following measurements will per- 

 haps better show the difference: — 



Breadth Thickness 



45 fi 35 p 



70 (i 45 \i 



Length 

 P. pellucidiim about 55 n 

 P. pallidum — 80 n 



The relation between the breadth and thickness is especially 

 very different, but they also differ as regards their whole appear- 



ance and the plan of 

 their transversal fissure, 

 which is nearly at right- 

 angles with the longitu- 

 dinal axis in P. pelluci- 

 diim, but very oblique 

 in P. pallidum. 



It is a boreal, oceanic 

 species, which is rather rare around the Færoes. [See tables.] 



74. P. Steinii J6rg., 1. c. p. 38; P. Michaelis Stein, 1. c, PI. 9, 



figs. 9 — 14; non Ehbg. 



Temperate, oceanic species, very rare around the Færoes (found 

 three times in July). 



75. P. globulus Stein, 1. c, PI. 9, figs. 5—8. 

 As the above, found only once in February. 



Fig. 131. Peridinium pallidum Ostf., a specimen from the North 

 Atlantic Ocean; the same cell in different views ( 200 /i). 



Sungen. 2, EUPERIDINIUM Gran. 



70. P. conicum (Gran) Ostenfeld & Schmidt, Vid. Medd. Nath. 



For., 1901, p. 174: Gran, Das Plankton des Norw. Nordmeeres, 



1902, p. 189, lig. 14; P. divergens, var. conica Gran, Rep. on the Nor- 



weg. Fishery and Marine Investigations, Vol. I, 1900, No. 5, p. 47; 



P. divergens, var. Michaelis Jorg., 1. c. p. 37. 



This species has not been distinguished from the following in most 

 of the samples; I am inclined to think thai it is not rare in the plank- 

 ton around the Færoes, but I have noticcd il only in some samples ol' 

 1900 (March and July) and 1902 (August). Gran describes il lullv in 

 his last treatise on plankton and gives figures of it; he also describes 

 an allied species, viz. P. pentagonum which I do not know. 



77. P. divergens Ehbg.; P. lenliculare (Ehbg.) Jorg., 1. c. p. 37. 



Occurs not infrequently in the planklon, hul not in any greal qua n ti ty, 

 found in January, March, July December. A temperate, oceanic species. 

 [See lables. | 



