Vol. 56.] 



UPPER CHALK AT COTXLSDON". 



"03 



This form agrees in outline with D. regularis, Perner, which is 

 figured in section only in ' Kadiolariich, etc.' Sitz. Bohm. Gesellsch. 

 Wissensch. 1891. 



DlCTYOMITRA sp. e. (PL XXXVIII, fig. 11.) 



The shell is broadly conical, smooth, with five segments of about 

 uniform height. Very fine reticulation, probably secondary. Height 

 of test =-20 mm. Breadth of last segment = # 11 mm. 



A form very similar to this occurs in the St. Pierre Shales, 

 Yankton (S. Dakota). 



DlCTYOMITRA Sp. £. (PI. XXXVIII, fig. 12.) 



Test with an oval outline, constricted somewhat at the base. 

 Xumber of segments uncertain. The pores are hexagonal and 

 arranged in slanting rows, but it is doubtful whether they are 

 original or due to corrosion. Height of test =*16 mm. Greatest 

 breadth =-08 mm. Breadth of base =*06 mm. 



Order STEPHOIDEA. 



Genus Zygostefsanus, Haeckel. 



Coronida with four large simple lateral gates, without basal gate 

 and lattice-work. Skeleton composed of two meridional rings 

 perpendicular one to the other. 



Zygostepranus aculeatus, Bust ? (PI. XXXVIII, fig. 13.) 



This form is very closely allied, if not identical with Z. aculeatus, 

 Bust, but is not quite so large as his form. It is figured in 

 1 Palaeontographica ' vol. xlv (1898) pi. vii, fig. 13 & p. 37. Greatest 

 breadth =*43 mm. 



The genera, and the number of species in each genus, of the 

 radiolaria found in Chalk-flints at Coulsdon, Surrey, may now be 

 tabulated as follows : — 



Species. 

 .. 4 

 .. 1 

 1 



Sub-class SPUMELLARIA. 

 Order Sph\eroidea. 



Genus Rhopalastrtim 

 Trigonactura, 

 Hagiastrum. 



Genus Cenosph&ra 



Species. 

 ... 2 



Gen 

 Gen 



Stauralastrum 



Sub-class NASSELLARI 



Order Cyrtoidea. 



us Cyrtocalpis 



Dicolocapsa 



Lithocampe 



Dictyomitra 



Order Stephoidea. 



2 



fifylosphfgra 



... 1 





Trilonche 



Acantkosphcera 



... 1 

 ... 2 



A 



Order Prunoidea. 

 Genus Lithapium 



... 1 



2 

 1 

 1 



Order Discoidea. 



Genus Theodiscus 



iSpongotripus 



... 1 



2 



10 

 1 



Trochodiscus 



Uncertain 



... 1 



... 4 



41 

 belonging to 20 



Coccodhcus 



... 1 



species, 

 genera. 



Trigonocyclia 



... 2 



