PLATE XL VI. 



Fig. 1.— RAPIIIDIOPHKYS. Probably B. viruUs. 



An individual which appeared bright green under lower powers. Ditches below Philadelphia, 

 June, 1874. 370 diameters. 



Fig. 2. A nearly colorless individual. Same locality. 500 diameters. 



Fig. 3. A colorless individual. Found with Spongilla, in Schuylkill River, Philadelphia, August, 

 1874. COO diameters. A more highly magnified spicule seen in the left. 



Figs. 4-6.— HETEROPHRYS MYRIAPODA? 



Fig. 4. A bright green individual, excepting the color, closely resembling an Aclhiophrys sol. Ab- 

 sccom pond, New Jersey, May, 1877. 250 diameters. 



Fig. 5. A bright green individual. Vinelaud, N.J. .August, 1876. 500 diameters. 



Fig. 6. A bright green individual. From sphagnum-water. Absecom, N. J., May, 1877. 



Figs. 7-10. -HETEROPHRYS ? 



FlG. 7. An individual showing a very great variability in the condition of the rays. Absecom 

 mill-pond, New Jersey, September, 1874. 500 diameters. 



FlGS. 8, 9. Two views of an individual exhibiting successive changes of shape. Found with 

 the former. 1,000 diameters. 



Fig. 10. A bright pea-grceu individual, with changeable form of body. Absecom pond, New 

 Jersey, May, 1877. 250 diameters. 



Figs. 11-13.— HETEROPHRYS ? Probably of the same species as the former. 



Fig. 11. A green individual, containing segments of Lyngbya, which have become red as a result 

 of digestion. 1,000 diameters. Ditch at roadside, near Darby, Pa. 



FlG. 12. A small individual, containing a large body, probably food, of unknown character. 

 Broad Mountain, Pennsylvania. 500 diameters. 



Fig. 13. An individual, containing apparently a number of unicellular algae variously colored. 

 Found with that of fig. 11. 1,000 diameters. 



