1893.J MICROSCOPICAL JOURNAL. 223 



Classification of the Radiolaria. 

 By REV. FRED'K B. CARTER, 



MONTCLAIR, N.J. 



In a fonner paper, (see this Journal for 1892), I gave a classi- 

 fication of the 42 genera found by Ehrenberg in the Barbadoes 

 deposit as arranged by Haeckel. That seemed a fairly large 

 number of genera for the student to make himself acquainted 

 with, but it proves to be child's ])lay in comparison with what 

 he must do to master these Barbadoes forms alone. For. in- 

 stead of 42, I find there are no less than 191 genera now known 

 to exist in that deposit or almost live times as man}^ as we con- 

 sidered. And here let me point out the richness of this Barba- 

 does earth, in other words, how remarkably representative it is 

 of all the fossil forms. 



The Radiolaria are divided by Haeckel into four legions, 

 namely, — 



Spumellaria, (or Peripylsea,) 

 AcANTHARiA, (or Actipyl«a,) 

 Nassellaria, (or Monopylsea,) 

 Ph.eodaria, (or Cannopylwa.) 



Now, " of these four legions, " he says, the" Acantharia, (o'\ 

 account of the solubility of their skeletons,) have en- 

 tirely vanished and have never been found fossil. Of the 

 Ph.eodaria, whose silicate skeleton is not, as a rule, capable of 

 fossilization, only one section (Didyo'chi da), of a single family 

 (CANNORHAPHIDA) has been observed fosdl. Hence the 

 fossil remains of the Radiolaria belong almost exclusively to the 

 two legions, Spumellaria and Nassellaria, which were form- 

 erly united under the term " Polycystina." * 



Now, the total number of genera described by Haeckel in the 

 Challenger Report, is 739. But, of these, 168 have only been 

 observed in the living condition. Hence the number of fossil 

 genera is 571. And of these, 191 genera, or fully one-third, have 

 been found in the Barbadoes deposit alone. But even that does 

 not tell the whole story. In the legion Spumellaria, all the 

 5 families of Sphseroidea are represented ; all the 7 families 

 of Prunoidea; and 4 out of the 6 families of Discoidea. 

 So that though there are no representatives of the 9 families of 

 * Challenger Report, Vol. 18, p. CIV. 



