50 kAark mlnstkf* strum. M.-N. Kl. 



.'. I'iniikinn I nun Silsvuiulrl . ' 

 Spccif.s wliii'li ari! rcpicscntcd upon the plali- arc: 



Stniirn^tntiii t^r (trilr, 



Ccrntitint liiniiiiliiirllii, 



(riyUiiiiii lilrKiiiliiirllii irstiiig-sf)(ircs. 



;. .Is/iliiiK liii(( /rom Ihr pldiikloii of Jolstrrj'itii/lrl. 



l'la Ir III. 

 Magnifu-atiDn of li^iii-cs i 40 diameters. 



/. ridiikloii /rom Lrmousjnrii. 

 Species; whieh are represented upon tiu' [date arc: 



('vrlotrlld roiiitd, 

 Xdiillniliiim mililo/'niim. 



2. I'liiiiktoii from J»lstcrxHvidrt. 

 Speeies vvhirh are represented upon the plate arc: 



Sltiitrastnim j<\nili/'rriim, 

 Diiiohrvoii rvliiiiiriciim. 



' In reality the x'arious collections were very much richer than may appear from the 

 photomicrographs. However, when making the film of water as thin as possible, the 

 specimens will consequently be very scattered on the object-plate. 



