EUGLENA. 161 



together and produce a zygospore, which after a season of rest 

 develops 1-3 large bi-ciliate macrospores, and these in turn 

 develop new coenobia. 



PANDORINA MORTJM, Bory. 



Coenobiuni spherical or somewhat oval, usually composed 

 of sixteen cells ; may vary by multiples of 8, from 8-64. 

 Zygospore with a smooth epispore. 



Diameter of coenobia up to 220 /<. 

 Diameter of vegetative cells, 9-15 //. 



Plate CLIII, figs. 1-5, the most frequent condition ob- 

 served ; figs. 6, 7, coenobia with more numerous cells 

 densely clustered ; figs. 8, 9, very fugacious coenobia ; placed 

 to this species with some hesitancy ; fig. 10, a matured coeno- 

 biurn ; the cells in condition for independent existence- 

 ready to escape from the maternal tegument. 

 In larger or smaller pools of stagnant water. 



Genus 35, EUGLENA, Ehrb., 



Cells more or less fusiform or elongate, mobile, exceedingly 

 flexible and changeable in shape, terminating posteriorly by a 

 more or less developed tail-like prolongation; anteriorly fur- 

 nished with a long flagellum by means of which they keep up a 

 forward and rolling or rocking motion. Increasing by longi- 

 tudinal division, and by the production of germs through the 

 subdivision of the cell contents. Usually they have a red 

 eye-spot. 



EUOKLENA VIRIDIS, Elirb. 



Cells elongate, subcylindrical or fusiform, exceedingly 

 flexible and variable in shape, mostly rounded anteriorly, 

 and with a short transparent tail-like posterior prolonga- 

 tion ; cell contents usually bright green, but sometimes 

 changing to dark orange or red. Flagellum slender, exceed- 

 ing the body in length ; a red pigment spot generally pres- 

 ent at the anterior extremity. After a longer or shorter 

 period of activity the cells come to rest, contract and assume 

 a spherical form and throw around themselves a gelatinous 

 envelope which gradually becomes indurate. These cells 

 under favorable circumstances divide into two and then 

 into four green cells ; finally the Euglena form is reproduced. 



Cells 40-62 ^ long. 



Common in stagnant waters. 



