KONGL. SV. VET. AKADEMIENS I1ANDLINGAK. BAND. 34. N:o I. 1 ] 



Sethoconus crinitus. N. 8p. 



I 'Inte III. Fig. 13. 



Cephalis subspherical large, with numerous bristle-shaped horns and close polygona] 

 meshes of different size. Collar constrictiori deep. Thorax conical, with straighl outline, 

 gradually inereasing in breadth towards thc uideopen mouth. Pores of the thorax similar 



to those of the cephalis, polygonal and of different size, nincli broader than the thread- 

 like bars. 



Cephalis 0,03 long and broad. Thorax 0,06 long and broad. Collar constriction 

 0,02 millim. 



Sparingly along the N. coast of S. America and in the Florida current, 7° — 41 X. 

 53°— 75° W. Temperature 22,4 to 28. Salinity 33,88 to 36,56. 



Sethocyrtis pyrum. N. Sp. 



Plate IV. Fig. 6. 



Shell thick-walled, pear-shaped, with slight collar stricture. Length of the two 



joints 1 : 6, breadth 1 : 4. Cephalis hemispherical, with a, small horn of half the length 



and unequal small pores. Thorax inflated, with circular, regular pores, quincuncially 



arranged and as broad as the bars. On the nodal points short spines arise. Mouth flat, 

 half as broad as the thorax. 



Cephalis 0,oi2 long, 0,02 broad. Thorax 0,072 long and 0,08 millim. broad. 



Very rare at 45° N. 49° W. (January 1899). Temperature 12. Salinity 35,54. 



Spermatogonia antiqua Leud. Fortm. 

 Plate III. Fig. 17, 18. 



Dr. Leuduger Fortmorel described in 1892 (Diatomées de la Malaisie. Annales du 

 Jardin botan. de Buitenzorg. Vol. XI pag. 49. Pl. IV, tig. 8) under the above name an 

 organism from the Malay Archipelago, which hc considered as a diatom. The figure has 

 been reproduced in Van Heurck's Treatise on the diatomacee (1896) pag. 541 with the 

 remark »is it a diatom?». This form is by no means rare in the tropical Atlantic and 

 cannot be a diatom. It is a part of an organism, of which I have however seen only 

 alcohol-preserved specimens. The neadles, called Spermatogonia, are by their arrow- hcad 

 like ends fastened in groups on a hyaline säck, which encloses, besides a number of 

 smaller granules, a larger cucumber-like body. This body, which treated with soda shows 

 a peculiar strueture of longitudinal and transverse lines, reminds of the central capsule 

 of the radiolarians. If so, the hyaline säck should correspond to the calymna. But, on 

 the other hand, there is no radiolaria known, wich offers any distant relation to 

 Spermatogonia. From the plueodarian it differs by the entirely different central capsule. 

 In all cases this form is no diatom, and, if a radiolaria, it belongs to a quite new type. 



