PLATE XV. 



Figs. 1-24.— DIFFLUGIA LOBOSTOMA. 



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

 sare centrally bright green ; the pseudopods protruded. Fig. 1, inferior view exhibiting the trilobed 

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



Figs. 3, 4. Similar views of another specimen found w T ith the former. 



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

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



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

 Philadelphia, May, 1875. 250 diameters. 



Fig. 8. Inferior view of an individual with quadrilobate 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, 1S77. 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 pseudopodal extension. Pitch below Philadelphia. 



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



Length, 0.14 mm. ; breadth, 0.13 mm. 



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

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



Fig. 14. Inferior view of an 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, 1870. 200 diameters. Length, 0.1155 mm. ; breadth, 0.05 mm. 



Figs. 10, 17. Two views of an empty shell, composed of rectangular and oval plates with dotted 

 intervals; tig. 10, inferior view exhibiting the quadrilobate mouth; tig. 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 an empty shell, composed of rectangular plates and fragments of dia- 

 toms; tig. 18, inferior view, exhibiting an irregular multilobatc (probably mutilated) mouth ; tig. 19, 

 lateral viow. Hammonton pond, New Jersey, September, 1877. 250 diameters. 



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

 diatoms. Atco, N. J., June, 1877. 350 diameters. 



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

 by a projecting rim. Woodstown poud, New Jersey, September, 1877. 250 diamoters. 



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

 lobed mouth. Swarthmore brick-pond. 250 diameters. 



Figs. 25-31.— DIFFLUGIA GLOBULOSA. 250 diameters. 



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

 food in 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 showing 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, irregu- 

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

 extended. Pond near Darby. Delaware Countx. 



Figs. 32, 33.— DIl'FLUGIA PYRIFOEMIS. 200 diameters. 



Two individuals showing their approximation in shape to the subpyriform varieties of Diflluyia 

 globulosa. Swarthmore brick-pond. 



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



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

 lateral view, with sand grains incorporated at the fundus; tig. 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 ami dirt. Tobyhanna sphagnous swamp, Pokouo Mountain, Pennsylvania, July, 1876. 



