50 Pp. T. CLEVE. PLANKTON, COLLECTED BY THE SWEDISH EXPEDITION TO SPITZBERGEN. 
Plate UL 
Pag. 
Fig. 1. Peridium (?) minutum CL.  and.c The same shell in different foci . ... . Bl. 
> 2. Phorticium pylonium HKL. «a, 8, ¢ The shell in different state of development, r ‘The primordial 
shell . 31. 
> 8. Plectanium (?) simplex Ch. ay re Sim : iy BRAM Ringe da AGRA. og 32. 
» 4. Polypetta holostoma CL. a “The shail, ) Structure... . : % 8 32. 
os Gg: OSs 
» 5. Theocorys borealis CL. . 
