70 THE PROTOZOA 



which the membrane of the central capsule is perforated by pores 

 arranged regularly about the entire surface (Fig. 34, A)\ (2) the Acti- 

 pylea, in which the pores are arranged in groups over the surface 

 (B); (3) the Monopylea, in which there is but one such group 

 of pores in the membrane. In these forms the perforated disk is con- 

 nected with the centre of the central capsule by a conical mass of 

 endoplasm, the podoconus (D\ rich in food particles and gran- 



D 



Fig. 34. Central capsules of Radiolaria. [H AECKEL.] 



A. Thalassolampe maxima Haeck., one of the Peripylea. B. Acanthometron dolichoscion Haeck., 

 one of the Actipylea. C. Aulogr aphis candelabrum Haeck., one of the Monopylea. D. Triptero- 

 calpis ogneoptera Haeck., one of the Cannopylea. c, central capsules; n, nuclei. 



ules ; (4) the Cannopylea, in which the membrane around the pores is 

 drawn out into funnel-like projections termed astropyles (C). The 

 central capsule is double in these forms. Haeckel has found that 

 certain skeletal forms accompany the structure of the membranes, and 

 he names the above legions respectively as follows : ( i ) Spumel- 

 laria ; (2) Acantharia ; (3) Nasselaria, and (4) Phceodaria, 



In each of the orders of the Sarcodina, and especially in the 

 Radiolaria, there are some forms with symbiotic plant-cells. The 



