PLATE XXXVIII. 



PLACOCISTA SPINOSA. 



Specimens mostly from the sphagnum of Absecom, N. J. 500 diameters. 



Figs. 1-5, 7, 9, 10, 13, 14. Broader side views. Figs. 8, 11, 12. Narrower side views. 



Fig. 1. Individual with the sarcodo contracted at the sides and retracted from the mouth of the 

 shell. October, 1875. 



Fig. 2. Individual in which the sarcodo fills the shell and emits pseudopods. Sphagnum of Atco, 

 N. J., April, 1877. 



Fig. 3. Individual obtained with the preceding. The sarcode constricted and exhibiting no con- 

 tractile vesicle. 



Fig. 4. Individual with protruded pseudopods ; the sarcode occupying a comparatively small pro- 

 portion of the cavity of the shell. October, 1875. 



Fig. 5. Individual with sarcode nearly filling the shell. October, 1874. 



Fig. 6. Upper view of an individual, with pseudopods protruded. Atco, N. J., May, 1877. 



Fig. 7. Individual, with the sarcodo contracted and supposed to be ready to pass into the encysted 

 condition. 



Fig. 8. Outline of the narrower side of the same specimen, showing the closed condition of the 

 shell below the position of the sarcode. October, 1874. 



Fig. 9. Individual in which the sarcode appears to bo shedding or discharging matter previous to 

 its assuming the encysted state. Found with the precediug, October, 1874. 



Fig. 10. Individual with pseudopods projected. Fig. 11. Outline of the narrower lateral view of 

 the shell of the same. October, 1674. 



Fig. 12. Outline of the narrower lateral view of an empty shell. 



Fig. 13. View of the broader side of the same specimen. 



Fig. 14. Outline of the broader side of a shell, which contained an empty lenticular shell, appar- 

 ently from an individual in the encysted condition, a, a spine attached to the shell in an unusual 

 position. 



Fig. 15. A detached spine highlv magnified. 



Fig. 16. Another spine more highly magnified, apparently exhibiting a waving condition. 



