REPORT ON THE RADIOLARIA. 



663 



I. Subfamily 



Amphitholida. 

 Cupolas developed only in 

 the direction of one < 

 single axis (commonly 

 two cupolas). (Tholonida 

 unidimensiva.) 



II. Subfamily 



Staurotholida. 

 Cupolas developed in the 

 direction of two axes per- 

 pendicular one to another 

 (commonly four cupolas). 

 (Tholonida bidimen- 

 siva.) 



III. Subfamily 



Cubotholida. 



Cupolas developed in the 

 direction of three axes 

 perpendicular one to 

 another (commonly six 

 cupolas). (Tholonida 

 tridimensiva.) 



Synopsis of the Genera of Tholonida. 



IT wo simple cupolas (with- 

 out veil), 

 .,.. ,., .. , rp j , , , , .., 



| Two double cupolas (with 

 veil), 





(Two simple cupolas (with- 

 out veil), 

 Two double cupolas (with 

 veil), 



Central chamber simple, 

 without medullary shell. 



Four simple cupolas 

 (without veil), 



Four double 

 (with veil), 



cupolas 



Central chamber Lamacilla- 

 shaped, with enclosed 

 medullary shell. 



Central chamber simple, 

 without medullary shell. 



f Four simple cupolas 

 (without veil), 



Four double 

 (with veil), 



cupolas 



Six simple cupolas (with- 

 out veil), 



Six double cupolas (with 

 veil), 



f Six simple cupolas (with- 

 Central chamber Larnacilla- out veil), 

 shaped, with enclosed < 

 medullary shell. Six double cupolas (with 



I veil), 



289. Tholartus. 



290. Tholodes. 



291. AmpMtholus. 



292. Amphitholonium. 



293. Tholostaurus. 



294. Tholoma. 



295. Staurotholus. 



296. Staurotholonium. 



297. Tholocubus. 



298. Tholonium. 



299. Cubotholus. 



300. Cubotholonium. 



Subfamily 1. AMPHITHOLIDA, Haeckel. 



Definition. T holonida with monaxial growth ; cupolas opposite on the poles 

 of one axis. (Shell commonly three-chambered, with two domes on both sides of the 

 central chamber.) 



Genus 289. Tholartus, 1 n. gen. 



Definition. T holonida with simple cortical shell (without external veil) ; with 

 two hemispherical cupolas, opposite on the poles of one axis ; central chamber between 

 them simple (without medullary shell). 



1 Tholartus = Cupola-bread ; 



