KONOr,. SV. VET. AKADEMIENS HANDLINnAH. BAND 34. N:0 I. 15 



I t'oiuid this species in samples from Spitzbergen, collected in August 1898 (80 

 31;N. 1<S.")0'K.) and the same month 1899 (80 N. l(iE.). Temperature 0,30 to 

 + 2,4-.>. ISnlinity ih,-M\ to 3;^, 9:). It is thus to be considered as an arctic neritic form. 



Ceratium paradoxides. N. Sp. 

 Plate VII. Fig. 14. 



I propose this name for a form, nearly akin to C. iunuJus. It is characterized by 

 the cellular reticulation of the membrane. I have seen it, but very rarely, in samples 

 from tiu' Xe\vfoun<lIaii(l Hanks, the Azores and the Canaries. 



Ceratium rauipes. N. Sp. 

 Phite VII. Fig. 1. 



This rare and remarkable form has been figured by Souutt in Pflanzenleben der 

 Hochsee, pag. 267, fig. 79, \'I1I b. but without name. Lemmekmann (Abh. Nat. Verein. 

 Breraens. Yo\. XVI, Part 2, pag. 346) names it C. tripos var. digitatum, but as Schiitt 

 has already used tlie name <li(/itatuin for another different species, a- new name becomes 

 necessary. 



This form occurs in the tropical Atlantic, in the Equatorial, Antilles and Florida 

 currents, also round the Azores, or between 12 and 49 N. 



Ceratium reflexum. N. Sp. 

 Phite VII. Fig. 8, 9. 



Tills form, characterized by the divergency of the posterior horns, of which one is 

 nearly parallel to the apical horn, is very rare and has been seen twice onl}-, viz. at 19 S. 

 31 W. and 38 N. 47 W. 



Ceratium (tripos var.?) volans. N. Sp. 



Pliite VII. Fig. 4. 



This form is characterized by the straight and very long posterior horns, which 

 proceed in a right angle to the apical horn. They become first towards the distal end 

 somewhat bent towards tlie apical horn. 



This species is common in the tropical Atlantic, and it may be possible that it is 

 the same as Ceratium earriense Gourret, which I dare not decide without comparing 

 original specimens. 



Ceratium (tripos var.?) vultur. N. Sp. 



Plate VII. Fig. 5. 



This species, which is characterized by the angular flexure of the posterior horns, 

 occurs frequently in chains. 1 have found it in samples from the Indian ocean and from 

 the tropical Atlantic between 21 S. and 45 N. 



