PLATE XXXII. 



Figs. 1-25.— COCHLIOPODIUM BILIMBOSUM. 



The dotted appearance in the broad band or zone, and in the double contour line, in most of the 

 figures, is intended to represent the finely cancellated structure of the investing membrane or shell, but 

 i» represented more distinct than natural. 



Fig. 1. Upper view of an individual, the broad dotted zone representing the expanded base 01 

 mouth of the shell. The nucleus seen centrally. 1,000 diameters. China Lake, Uinta Mountains, 

 August, 1877. 



Fig. 2. Individual with the basal border of the shell expanded on one side — in the direction of 

 movement of the animal. With the preceding. 1,000 -|-. 



Fig. 3. Upper view of an individual, with the basal border extended nearly all around. Among 

 alga?, in ditches below Philadelphia, May, 1875. 1,000 -f. 



Fig. 4. Individual with pseudopodal extensions opposite the extension of the basal border of the 

 shell, and in the act of discharging excrementitious matter. 500 -4-. Among water-cress, in a spring 

 on Darby Creek, Delaware County, Pennsylvania, April, 1875. 



Fig. 5. Lateral view of an individual, with pseudopods extending from beneath the expanded 

 basal baud of the shell. 1,000 +. Ditch below Philadelphia, April, 1876. 



Fig. 6. Lateral view of au individual, with extended pseudopods, hut with the basal band of the 

 shell contracted. 500 -4-. Found with fig. 4. 



Fig. 7. Lateral view of an individual; with extended pseudopods, and extension of the basal 

 band of the shell. With the preceding. 500 +. 



Fig. 8. Lateral view, with pseudopods, and with the basal band of the shell contracted. 500 +■ 

 Fort Bridger, Wyoming, August, 1877. 



Figs. 9, 10. Lateral and upper views of an individual. 500 -f. Spring on Darby Creek, Delaware 

 County, Pennsylvania, April, 1875. 



Fig. 11. Lateral view, with the basal band of the shell drawn into folds. Same locality. 



Fig. 12. Upper view, with extension of the basal band on one side and a pseudopodal extension 

 on the opposite side. With the preceding. 



Fig. 13. Upper view, with inflection of the basal band, and projection of pseudopods. With the 

 preceding. 



Figs. 14-17. Four successive views of the same individual seen from above. Fig. 14, with in- 

 flected basal band ; fig. 15, the baud extended on one side ; figs. 16, 17, the band widely expanded all 

 rouud. Iu all, pseudopodal extensions are seen, but their appearance across the basal band is drawn too 

 darkly. Same locality as the preceding. 



Figs. 18, 19. Two views of an individual ; in the former as it. appeared either spread upon or 

 attempting to swallow a large diatom; in the latter, as it disengaged itself from the diatom, moving off 

 in the direction of the expanded basal band. With the preceding. 



Fig. 20. Lateral view of a small individual, with inflected basal border, and with projected pseudo- 

 pods. Among alga? at foot of fountain in front of City Hall, Market street, Philadelphia, August, 1878. 



Figs. 21, H2. Two views of an individual, with broad basal band, in which the punctated appear- 

 ance could not lie detected. With the preceding. 



Fig. 23. Small individual, seen from above, with widely expanded basal band, in which no trace 

 of the cancellated structure could be detected. Swarthmore, Delaware County, Pennsylvania, May, 1875. 



Fig. 24. Lateral view of a specimen acted on by ammoniacal solution of carmine; the nucleus 

 deeply stained. 



Fig. 25. Lateral view of a specimen acted on by a feeble solution of iodine in potassium iodide. 



Figs. 26-28.— COCHLIOPODIUM VESTITUM. 500 -f. 



Fig. 26. Lateral view of an individual, with the basal baud of the shell thrown into angular 

 folds, and with the interior sarcode containing a large quantity of chlorophy] granules. Absecom pond, 

 New Jersey, May, 1865. 



Fig. -'7. Lateral view of a colorless specimen. Same locality, September, 1874. 



Fig. 28. Lateral view of an individual, with yellowish shell, and with extended pseudopods. 

 Uinta Mountains, Wyoming, August, 1877. 



Figs. -.9-37.— CENTEOPYXIS ACULEATA. 



Figs. 29, 30. Lateral and inferior views of an empty shell, composed of chit iuoid membrane. 500 -f. 

 Tobyhanna, Pokono Mountain, Pennsylvania. 



Fig. 31. Lateral view ot an empty shell of chitinoid membrane. 500-)-. Sphagnum, Absecom, N.J. 



Figs. 32, 33. Oblique lateral and inferior views of au empty shell. 250 -f. Same locality as 

 preceding. 



Fig. 34. Inferior view of a shell composed of chitinoid membrane, with incorporated diatoms. 

 Empty and deeply stained brown. 350 +. Ditch below Philadelphia. 



Figs. 35, 36. Inferior aud lateral views of a spineless shell, pertaining to the variety Centropyxia 

 coornis. The shell composed of chitinoid membrane incorporated with largo sand grains. 250+. 

 Sphagnum, Absecom, N. J. 



Fig. 37. Inferior view of a shell, composed of chitinoid membrane with sand. 250 -f. Swarth- 

 more brick-pond. Delaware County, Pennsylvania. 



