from the " Cambridge Greensand." 311 



Cristellaria rotulata (Lam.). 



Lenticu'ites rotulata, Lamarck, 1804, Annales dii Museum, vol. v. 



p. 188, no. 3 ; Tableau Encvcl. et M»5th. pi. ccccLvvi. fig. o. 

 Cristellaria rotulata (Lara.), d'Orbigny, 1840, M6m. See. g4ol. France, 



8^r. 1, vol. iv. p. 2G, pi. ii. figs. 15-18 j Chapman, 1896, Journ. R. 



Micr. Soc. pp. 5, 6, pi. i, figs. 8 a, b. 



This species was recorded by G. E,. Vine from Cambridge. 

 It is common at Swaffham. 



Cristellaria rotulata (Lam.), var. macrodiscus^ Reuss. 



Cristellaria macrodisca, Reuss, 1862, Sitzungsb, d. k. Ak. Wiss. Wien, 



vol. xhi. p. 78, pi. ix. figs, o a, b. 

 Cristellaria rotulata {lj-AVii.),\&v. macrodiscus, Reuss, Chapman, 1896, 



Journ, R. Micr. Soc. pp. 6, 7, pi. i. figs. 9 a, b. 



This variety is frequent at SwafFhara. 



Cristellaria gaultina^ Berthelin. 



Cristellaria gaiiltina, Berthelin, 1880, ^fem. Soc. g6ol. France, ser. 3, 

 vol. i. no. o, p. 49, pi. iii. figs. 15-19 ; Chapman, 1896, Journ. R. 

 Micr. Soc. pp. 7, 8, pi. i. figs. 10 «, b, 11. 



This species ranges throughout the Gault, besides occurring 

 at several horizons above the Cenomanian. In the Cambridge 

 Greensand of Swaffham and elsewhere C. gaultina is exces- 

 sively common and attains to a great size, some specimens 

 being 3 raillim. across the disk. 



Cristellaria sternalis, Berthelin. 



Cristellaria sternalis, Berthelin, 1880, Mem. Soc. geol. France, ser. 3, 

 vol. i. no. 5, p. 54, pi. iii. figs. '2 a, b; Chapman, 1896, Journ. R. 

 Micr. Soc. p. 8, pi. ii. figs. 1 a, b. 



This species does not attain to so large a size in the Cam- 

 bridge Greensand as in the Gault. It is frequent at 

 Swaffham. 



Cristellaria diademata, Berthelin. 



Cristellaria diademata, Berthelin, 1880, M(5m. Soc. geol. France, S(5r, 3, 

 vol. i. no. 5, p. 51, pi. iii. figs. 4, 5, 12, & 13 ; Chapman, 1896, 

 Journ. R. Micr. Soc. p. 8, pi. ii. figs. 2 a, b. 



One fine specimen from the Greensand of Swaffham. 



