696 ME. W. M. HOLMES ON EADIOLAEIA PEOM THE [Nov. I9OO, 



That radiolaria existed in considerable numbers in the Cretaceous 

 seas is proved by the fact that in the small quantity of material 

 examined forty-one species, belonging to twenty genera, have been 

 recognized. 



As in the case of the smectite of Belgium, the Discoidea appear 

 to predominate. Next in numerical order must be mentioned the 

 species of Dictyomitra. 



My thanks are especially due to Dr. G. J. Hinde, F.R.S., who has 

 very kindly examined the specimens, besides helping me with advice 

 and furnishing me with literature on the subject. His experience 

 in examining fossil radiolaria makes such help invaluable. 



Class RADIOLARIA, Miiller. 



Sub-class SPUMELLARIA, Ehrenberg. 



Order SPHJEROIDEA, Haeckel. 

 Genus Cenosph^ra, Ehrenberg. 

 The test is a simple latticed sphere without radial spines. 



Cjsnobfbjera sp. (PI. XXXVII, fig. 1.) 



Test small. Surface rough, with short spines between the pores, 

 which are circular or subangular. Diameter of test =*1 mm. This 

 corresponds in size with C. scitula, Hinde, described and figured in 

 Quart. Journ. Geol. Soc. vol. lv (1899) p. 43 & pi. viii, fig. 2, and 

 with C. minuta (Pantanelli), c Paiaeontographica ' vol. xxxiv (1888) 

 p. J 90. 



Cenospha^ra gregaria, Rust. (PI. XXXVII, fig. 2.) 



Test smooth. Pores uncertain. Diameter ='19 mm. Thickness 

 of test = "15 mm. 



Genus Stylo sph jura, Ehrenberg. 



The test consists of two concentric latticed spheres, with two 

 radial spines. 



Sttlosphjlra sp. (PI. XXXVII, fig. 3.) 



This specimen is much corroded, and the spines are imperfect. 

 Diameter of test ='10 mm. Only faint indications of a medullary 

 shell. 



Genus Teilowche, Hinde. 



The test consists of two concentric latticed spheres, with three 

 radial spines at equal or unequal distances apart. Secondary surface- 

 spines are also present sometimes. 



