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 pseudopoda protruded. Fig. 1, inferior view exhibiting the trilobed 

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



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



Figs. 5,0. Similar views of an empty shell with quadrilobate mouth. Pond noar 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. Iuferior view of an individual with quadrilobate mouth and colorless Barcode. China 

 Lake, Uinta Mountains, Wyoming Territory, August, 1877. Length, 0.18 mm, ; breadth, 0.13 mm. 



FlG.9. Iuferior view of an individual with qninqnelobatc month and colorless sarcode. Fort 

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



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

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



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

 Length, 0.14 mm. ; breadth, 0.13 mm. 



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

 spread out beneath the edge of a Holman life-slide. Found with tin 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. 200 diameters. Lengtb, 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. 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; lig. 17, lateral view showing pro- 

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

 diameters. 



Figs. 18, 10. Two views of an empty shell, composed of rectangular plates and fragments of dia- 

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

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



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

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



Figs. 21, 22. Inferior and lateral views of a mammillated 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 hemispheroidal specimen, with five- 

 lobed mouth. Swarthmore brick-pond. 250 diameters. 



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



Flos. 25, 20. Two views of the same individual, with colorless sarcode. except the color due to 

 fooil in the endosarc; tig. 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 pseudopoda ; 

 lig. 27, lateral view showing a projecting rim to the mouth; lig. 28, inferior view showing the huge 

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



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



FlG. 31. Lateral view of an individual, with the shell composed of chilinoid membrane, irregu- 

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

 extended. Pond near Darby, Delaware Countj . 



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



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

 globulosa. Swarthmore brick-pond. 



Figs. 34-37.— DIFFLUGIA AECULA. 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; lig. 35, iuferior view showing the trilobate 

 mouth. Sphagnons bog of Absecom, X. J., April, 1876. 



Figs. 30, :;7. Two similar views of a specimen composed of chitinoid membrane with incorporated 

 sand and dirt. Tobyhanna sphaguous swamp, Pokono Mountain, Pennsylvania, July, 1876. 



