RADIOLARIA 521 



Fig. 220 a, Lampoxanthium pandora, X20 (Haeckel); b, Thalassicolla 

 nucleata, X15 (Huth). 



Genus Thalassophysa 



Nuclear wall crenate 



Huge double spicule Family 4 Thalassothamnidae 



Genus Thalassothamnus 



A latticed skeleton, with branching and thorny spines 



Family 5 Orosphaeridae 



Genus Orosphaera 



Solitary, skeleton complex, often concentric 



Central capsule and skeleton spherical Family 6 Sphaeroidae 



Genus Hexacontium (Fig. 221, a) 



Central capsule and skeleton elliptical or cylindrical 



Family 7 Prunoidae 



c 



iri* * #^ 



Fig. 221. a, Hexacontium aster acanthion, X130; b, Pipetta tuba, X100; 

 c, Staurocyclia phacostaurus, X130; d, Cenolarus primordialis, X100; 

 e, SphaerQZoum ovodimare, X30 (Haeckel). 



