SPECIAL MORPHOLOGY AND TAXONOMY OF SARCODINA 343 



Sub-class 2. RADIOLARIA, Joh. Muller. 



The great number of genera of Radiolaria make it impossible to give 

 more than a superficial survey of this group. The four Legions of Hertwig 

 and of Haeckel are regarded as Orders m the following description, and 

 differ according to the arrangement of pores (pylea) in the central capsule 

 (Fig. 151). 



Fig. 151.— Radiolarian central capsules. A, Thalassolampe, type of peripylea; 

 B, Acanthometron, type of actipylea, C, Aulographis, type of tripylea; D, Triptero- 

 calpis, type of monopylea; c, central capsule; n, nucleus. (From Calkins after 

 Haeckel.) 



Order 1. PERIPYLEA, Hert. 



The Peripylea (also called Spuinellaria) are characterized by the 

 possession of a spherical central capsule with pores distributed 

 uniformly; a skeleton is generally absent or represented by scattered 

 spicules; colony formation is frequent, the colonies often measuring 

 several millimeters (Collozoum) or even centimeters. Nuclei are 

 multiple as a rule, but in some types a single huge nucleus apparently 

 represents the aggregate of nuclei in the multinucleate forms and 

 is regarded as a polyenergid by some writers (Hartmann, et al). 



Following the majority of recent writers we divide the Peripylea 

 into three sub-orders— Sphserellaria, Polycyttaria, and Collodaria. 



