clxxxviii 



THE VOYAGE OF H.M.S. CHALLENGER. 



1883. Eenst Haeckel (L. N. 46) revises the 4 orders and 32 families of Radiolaria, and gives 

 more accurate definitions of them, as well as of the 2 subclasses (I. Holotrypasta 

 = AcANTHARiA and Spumellaeia ; II. Alerotrypasta — Nassellaeia and Ph^odaeia). 



1885. D. Rust (L. N. 51) describes 234 new species of fossil Eadiolaria from the Jura, and illustrates 

 them by twenty plates. Among them are 103 Spumellaeia, 130 Nassellaeia, and 

 1 Ph^odaria; these are contained in 35 genera, of which 20 belong to the Porulosa, and 

 15 to the Osculosa. 



254. Statistical Synopsis of the Twenty Orders. 



A'b<«.-— In the tenth and eleventh columns the relative abundance of each order at or near the surface and near the bottom is approxi- 

 mately indicated by the letters A-E, which have the following significance :— A, abundant ; B, very numerous ; C, many (medium quantity) ; 

 D, few ; E, very few. 



