PLATE XV. 



Figs. 1-24.— DIFFLUGIA LOBOSTOMA. 



Figs. 1, 2. Two views of the same individual ; the shell composed of coarse quartz sand ; endo- 

 sarc centrally bright green ; the pseiidopods protruded. Fig. 1, inferior view exhibiting the trilobed 

 mouth ; fig. 2, lateral view. Swarthmore brick-pond, June, 1874. 200 diameters. 



Figs. 3, 4. Similar views of another specimen found with the former. 



Figs. 5, 6. Similar views of an empty shell with qu.adrilobate mouth. Pond near Darby, Dela- 

 ware County, Pennsylvania, October, 1874. 250 diameters. 



Fig. 7. Lateral view of an individual, with trilob.ite mouth and projecting rim. Ditch below 

 Philadelphia, May, 1875. 250 diameters. 



Fig. 8. Inferior view of an individual with quadiilobate mouth and colorless sarcode.. China 

 Lake, Uinta Mountains, Wyoming Territory, August, 1877. Length, 0.18 mm. ; breadth, 0.16 mm. 



Fig. 9. Inferior view of an individual with quinquelobate mouth and colorless sarcode. Fort 

 Bridger, Wyoming, August, 1877. 200 diameters. Length, 0.112 mm. ; breadth, 0.1 mm. 



Fig. 10. Inferior view of an individual -with six-lobed mouth, the margin stained brown. Fig. 

 11. Side view of the same with remarkable pscudopodal extension. Ditch below Philadelphia. 



Fig. 12. Inferior view of a similar individual. Fort Bridger, Wyoming Territory, July, 1877. 

 Length, 0.14 mm. ; breadth, 0.13 mm. 



Fig. 13. Side view of au individual with a seven-lobed mouth. Apjjearauce of the pseudopod, 

 spread out beneath the edge of a Hohnan life-slide. Found with the preceding. 



Fig. 14. Inferior view of au individual -with seven-lobed mouth ; the sand grains of the shell out- 

 lined with brown cement. Darby Creek, Delaware County. 250 diameters. Length, 0.14 mm. ; 

 breadth, 0.12 mm. 



Fig. 15. Small individual with trilobed mouth, inferior view, with profuse extension of pseudo- 

 pods. Ditch below Philadelphia, April, 1876. 200 diameters. Length, 0.055 mm. ; breadth, 0.05 mm. 



Figs. 16, 17. Two views of an empty shell, composed of rectangular and oval plates with dotted 

 intervals; fig. 10, inferior view exhibiting the quadrilobate mouth; fig. 17, lateral view showing pro- 

 jecting rim of the mouth. China Lake, Uinta Mountains, Wyoming Territory, August, 1877. 500 

 diameters. 



Figs. 18, 19. Two views of au empty shell, composed of rectangular plates and fragments of dia- 

 toms; fig. 18, inferior view, exhibiting au irregular multilobate (probably mutilated) mouth ; fig. 19, 

 lateral view. Hammouton pond, New Jersey, September, 1877. 250 diameters. 



Fig. 20. Lateral view of a specimen with trilobed mouth, composed of thin angular plates and 

 diatoms. Atco, N. J. , June, 1877. 250 diameters. 



Figs. 21, 22. Inferior and lateral views of a mamnullated specimen with six-lobed mouth bordered 

 by a projecting rim. Woodstown pond, New Jersey, September, 1877. 250 diameters. 



Figs. 23, 24. Inferior and lateral (reversed) views of a small heniispheroidal specimen, with five- 

 lobed mouth. Swarthmore brick-pond. 250 diameters. 



Figs. 25-31.— DIFFLUGIA 6L0BUL0SA. 250 diameters. 



Figs. 25, 26. Two views of the same individual, with colorless sarcode, except the color due to 

 food iu the endosarc; fig. 25, lateral view ; fig. 26, inferior view exhibiting the circular mouth. Swarth- 

 more brick-pond. 



Figs. 27, 28. Two views of the same individual, with colorless sarcode and extended pseudopods ; 

 fig. 27, lateral view showing a projecting rim to the mouth ; fig. 28, inferior view 8ho^ving the large 

 circular mouth. Fort Bridger, Wyoming, August, 1877. 



Figs. 29, 30. Two similar views of a specimen. Ditch below Philadelphia, September, 1875. 



Fig. 31. Lateral view of an individual, with the shell composed of chitinoid membrane, iiTcgn- 

 larly striated and incorporated with a few scaMerod sand grains. A single pseudopod enormously 

 extended. Pond near Darby, Delaware County. 



Figs. 32, 33.— DIFFLUGIA PYRIFORMIS. 200 diameters. 



Two individuals showing their approximation iu shape to the snbpyriform varieties of Difflugia 

 globwlosa. Sw.arthmore brick-pond. 



Figs. 34-37.— DIFFLUGIA AECULA. 250 diameters. 



Figs. 34, 35. Two views of an empty shell, composed of olay-oolorod chitinoid membrane ; fig. 34, 

 lateral view, with sand grains incorporated at the fundus; flg. 35, inferior view showing the trilobate 

 mouth. Sphagnous bog of Absecom, N. J., April, 1876. 



Figs. 36, 37. Two similar views of a specimen composed of chitinoid membrane with incorporated 

 sand and dirt. Toliyhauua sphagnous swamp, Pokono Mountain, Pennsylvania, July, 1876. 



