KEPORT ON THE RADIOLARIA. 



•209 



Sijnoims of the Genera of AstrosphcBrida — continued. 



VI. Subfamily 



Spongiommida. 



(Spherical shell whole or 

 partly spongy, with or 

 without enclosed latticed 

 medullary shells in the 

 centre. ) 



I. Tribe 

 Spongo- 

 drymida, 

 without 

 latticed 

 medullary 

 sheU. 



II. Tribe 



Ehizopleg- 



mida, 



with 



one single 



latticed 



medullary 



shell. 



Medullary 



shell 

 spherical. 



Medullary 

 shell a 

 simple 

 cube. 



III. Tribe Ehizosphaerida, 

 with two concentric 

 latticed medullary 



shells. 



Framework arising from 

 the medullary shell, 



,^ , f No medul- 



la ramework , 1 



separate ' y J 



from the ^P"^^^' " 



|_ by-spmes, 



f Framework arising imme- 

 I d lately from the medul- 

 J lary shell, . 



Framework separate from 

 the medullary shell, 



f Framework arising from 

 I the medullary shell, 



I 



1 

 I Framework .separate from 



1^ the medullary shell. 



115. Spongopila. 



116. 



11/ 



118. 



119. 



120. 



121. 



RMziiplegma. 

 Lychnosphcera. 



Centrocuhus. 

 Oetodendron. 

 Spongosphcera. 

 RhizospJtiera. 



Subfamily Coscinommida, Haeckel. 



Heliosphmrida, Haeckel, 1881, Prodromus, pp. 449, 450. 

 Dejinition. — A strosphserida with one single spherical lattice-shell. 



Genus 88. Acaiithosphoera} Ehrenberg, 1858, Monatsber. d. k. preuss. Akad. d. 



Wiss. Berlin, p. 12. 



Dejinition. — A strosphserida with one simple lattice-sphere, covered with 

 simple radial spines of the same kind. 



The genus Acanthosphcera exhibits the most simple form of all Astrosphaerida ; a 

 simple spherical lattice -shell, the surface of which is covered by radial spines of one and 

 the same kind. The number of the latter is very variable, often twelve to twenty, 

 regularly disposed ; in other cases forty to sixty or more ; and sometimes at each nodal - 

 point of the network a spine is developed. 



1 Aca7Uhosphccra = STpmy sphere ; axaaSa. (i(pait>a,. 

 (ZOOL. CHALL. EXP. — PART XL. 1885). 



Er 27 



