587 



Fig. 143. Ceratium longipes, var. oentricosa 

 Ostf., n. var. ('■"" . ,;. 



C. longipes, var. ventricosa n. var. 



In a few samples from the Færoes (August 1900) and also in 



others from the North Atlantic Ocean, I saw a Ceratium which 



comes near to C. longipes, but is easily 



distinguished from it by its much 



larger >trunk«. As I have only seen 



a few specimens, I am not prepared 



to define ils relation to the above- 



mentioned species; it appears to be 



analogous to C. compressum Gran, 



which comes near to C. horridum. 

 Note 1. C. arcticum Ehbg., which (Iran 



il. c. p. fil) found in the sea between the Færoes 



and the Shetlands, has not heen met with in 



the samples from the Færoes, although it may 



certainly occur there. C. inaequale Gourret 



(C. reticulatum Ostf., Iagttagelser 1899, p. 58, vix Pouchet) has 

 been found in the North Atlantic Ocean, SW. of the Færoes 

 and may also occasionally extend to them. 



Note 2. Besides the above-mentioned two sections of 

 the subgenus Euceratium various other sections may be 

 founded for the reception of the numerous tropical species. 



Subgen. 2, BICERATIUM Vanhoffen. 



84. C. lineatum (Ehbg.) Cleve, Kgl. Sv. Vel. 

 Akad. Handl., Bd. 32, Nr. 3, 1899, 

 p. 36; Peridinium lineatum Ehbg.; C. 

 farca v. baltica Mobius; Biceratium 

 debile Vanhoffen, Gronland Expedi- 

 tion d. Gesellsch. f. Erdkunde zu Ber- 

 lin; PI. 5, fig. 16. 



This little species, the small si/c 

 of which enables it to escape through 

 the meshes of the gauze, has only been 

 found twice in February along the Færoes; the speci- 

 mens examined have short horns. 



85. C. furca (Ehbg.) Clap. & Lachm. 

 Occurs rather sparingly around the Færoes, mostly 



together with C. tripos and the following species; found 

 during most of the months. [See tables.] 



Subgen. 3, AMPHICERATIUM Vanhoffen. 



86. C. fusus (Ehbg.) Dujard. 

 Hather common in the plankton and found all 



Fig. 144. Ceratium 

 lineatum (Ehbg.) 

 Cl., a short-horn- 



ed form (' ", ,)■ 



Fig. 145—1 16. 



FJg. 145. Ceratium fusus 

 (Ehbg. Huj.; the common 

 form from the sea around 

 the Fa-roes ('■"",!). - Fig. 146. 

 Ceratium fusus (Ehbg.) Duj. ; 

 a robust form with rather 

 short horns (^°li). 



