KONGL. SV. VKT. AKAUEMIENS HANULINGAH. ISANI) 34. N:() I. 13 



Trj p;inosph.Tra brachysiplioii. N. Sp. 



Plate VI. Fig. 3. 



Shell a regular sphere. Pores of unequal size; the larger prolonged in a very sliort 

 tube, with two or three teeth. 



Diameter: 0,i5, of the larger [)ores 0,oi7 milliui. 



Found very rarely at 56 N. 17 W. (November 189S) and at IT^N. G6 W. (De- 

 cember 1898). Teiiipernt'uro 11/; to 12. Salinity 34, eo to 35,J5. 



III. DINOFLAGELLAT^. 



Ceratiuiu (tripos var.) arcuatum Gouuret. 

 Plate VII. Fig. 11. 



GouRRET has described (Ann. du Musee d'Hist. Naturelle de Marseille; zool.. Vol. I 

 1883 n:o 8, pag. 25, PI. II, Hg. 42) a form of C. tripos, which I consider, although with 

 a some hesitation, to be identical with the Atlantic form. 



It is rather common in the tropical Atlantic from 29 S. to 48 N. 



Ceratium (tripos var.) arietimiiii. X. Sp. *) 

 Plate VII. Fig. 3. 



This form, Avhich belongs to the tripos-type, is very constant and could be consi- 

 dered as a distinct species. I have seen it in samples from the Indian Ocean and the 

 Atlantic, chiefly on the area between the Azores, the Engl. Channel and New York. It 

 occurs besides, but sparingly, in the N. Equatorial current, the Antilles current and in 

 the Caribbean Sea. It belongs to the si yli- plankton. 



Ceratium (tripos var.) azoricuni. N. Sp. 



Plate VII. Fig. 6, 7. 



This form is nearly related to the typical C. tripos, but differs by smaller size and 

 short apical horn. It occurs round the Azores and W. of the Spanish Peninsula. I have 

 also met with this form in plankton from "25 S. 7 E. 



Ceratium (furca var.?) belone. N. Sp. 

 Plate VII. Fig. 13. 



This form, which is evidently nearlj- akin to C. furca, is very rare in the Atlantic 

 and has been found in samples from 10 N. 53 W. and 33 34 N. 15 12 W., thus 

 in the western and eastern tropical Atlantic. 



*) J0RGENSEN (Bcrgeus Museums Aarbog 1899, X. \'I, I'l. II. tig. 1 1) names tliis form Ccfafiiiiii tiipos 

 arcuatum forma heterocampta. j0RGENSElsS work was not iiul)lislied when this jiaper was written. 



