PLATE XXIV. 



Figs. 1-10.— NEBELA CAEINATA. 



Fig. 1. Broader lateral view of a living individual, with protruded psendopods, and shell com- 

 posed of thin plates of variable shapes. Fig.2. Outline of the narrower side view. Fig.:!. Transverse 

 section with outline of the mouth. Sphagnum of Absecom, X. J., June, 1877. 2E0 diameters. 



Fig. 4. Broader lateral view of an individual in which the sarcode is of greater proportionate 

 extent than in the preceding, and the shell composed of plates of varied shapes has also a few particles 

 of sand attached — a rare occurrence in any species of Nebela. Absecom, October, 1874. 350 -f . 



Fig. 5. Individual with Barcode contracted into an oval ball, and throat of shell closed by a lami- 

 nated operculum. The shell composed of thill angular plates. Sphagnum, Swarthmnre, Delaware 

 County, Pennsylvania, June, 1877. 200 -f . Breadth of shell. I'.KiS mm. by 0.04 mm. 



Fig. 6. View of one-half of the broader side of an empty shell, composed of round and oval plates 

 of very unequal sizes. Absecom, X. J. Shell, 0.088 nini. by 0.036 mni. 5C0+. 



Fig. 7. More highly magnified view of a portion of the same under a different focus. 



Fig. 8. View of one-half of an empty shell with a comparatively narrow carina; the shell com- 

 posed of large oval plates, with small and mostly circular ones in the intervals. Absecom, X.J. 350-)-. 



Fig. 9. View of one-half of the broader side of an empty shell with a wide or deep carina; the 

 shell composed mostly of minute round plates, intermingled with linear plates and a few large oval 

 ones. Absecom, X. J. 350 -)-. 



Fig. 10. Empty shell, with broad keel, composed of chitinoid membrane incorporated with scat- 

 tered particles of sand, etc. Absecom, X T . J. 100 diameters. 



Figs. 11, 12. -XEBELA COLLARIS. 



Fig. 11. Empty shell, composed of chitinoid membrane, incorporated with thin angular silicions 

 plates, separated by narrow intervals. Sphagnum, Vineland, X. J., September, 1876. 250 diameters. 

 A similar specimen found on Broad Mountain, Pennsylvania, with shell 0.1 mm. long, and 0.088 mm. by 

 0.02 mm. broad. 



Fig. 12. Empty shell composed of thin, irregular, angular silicions plates in close juxtaposition. 



500 di a ters. Breadth of shell 0.0G4 mm. by 0.02 mm. This and the preceding form are transitional 



to the compressed variety of Difflugia pyriformis. 



Fig. 13.— XEBELA HIPPOCREPIS. 



An empty shell, with inflected hollow, spur-like processes ; the shell composed of circular over- 

 lapping plates. Absecom pond, Xew Jersey, September, 1876. 250 diameters. 



Figs. 14-17.— NEBELA BARBATA. 500 diameters. 



Fig. 14. Broader lateral view of an individual, the shell nearly replete with the sarcode and with 

 projected psendopods. The entire surface of the shell hirsute. Sphagnum water, Absecom, Septem- 

 ber, 1875. 



Figs. 15, 16. Two views of au individual, with the sarcode withdrawn into the body of the .shell. 

 Same locality. 



Fig. 1". Individual with the sarcode contracted into a ball, and with the neck of the. shell occu- 

 pied with discharged excrementitious matter. Same locality. 



Figs. 18, 19.— NEBELA. 



Fig. 18. An empty shell, the broader lateral view, reversed, composed of circular plates of un- 

 equal size. Intermediate in character to Nebela barbata and Nebela collaris, being shaped like the former, 

 but without cils as in the latter. Absecom, N. J., April, 1875. 500 -)-. 



Fig. 19. An empty shell nearly like the. former. China Lake, Uinta Mountains, Wyoming Ter- 

 ritory, August, 1877. 100-)-. 



Figs. 20-25.— QUADRULA SYMMETRICA. 



FlG. 20. Lateral view of a living individual. Around the base of the sarcode there were numerous 

 detached plates like those of the shell. Pond at Vineland, N. J., September, 1876. 500 +. 



Figs.21,22. Two empty shells. Absecom pond, N. J. 500+. 



Fig.2:!. Empty shell. Ditch on the Schuylkill, above Manayunk, Philadelphia, April, 1877. 



Fig. 24. Plates of a similar shell highly magnified. 



FlG.25. Broader lateral view of an individual in which the sarcode is contracted into an oval 

 discoid ball, and the mouth of the shell is closed with a thick laminated operculum. The plates of the 

 shell arranged in a much more diagonal course than usual. Sphagnum, Absecom, N. J., October, 1874. 

 350 diameters, 



