from the " Cambridge Greensand." 333 



Family Bairdiidae. 

 Bairdia, M'Goy, 1844. 



Bairdia subdeltoidea (Minister). 



Cythere subdeltoidea, Miinster, 1830, Jahrb. fiir Min. &c. p. 64, no. 13, 



1835, p. 440. 

 Bairdia subdeltoidea, Jones, 1849, Mon. Eat. Cret. p. 23, pi. v. fig. 15; 



Jones and Hinde, 1890, Suppl. Mon. Cret. Entom. pp. 5-7, pi. ii. 



figs. 31-34. 



A well-known form throughout Cretaceous strata as well 

 as in some Tertiary beds, B. subdeltoidea is already known 

 from the Cambridge Greensand. It occurs in some abun- 

 dance at Swaffham. 



Bairdia Harrisiana, Jones. 



Bairdia Harrisiana, Jones and Hinde, 1890, Suppl. Mon. Cret. Entom. 

 p. 8, pi. ii. figs. 52-55. 



With a range through the Gault to the Chalk, this species 

 has been previously noted from the Cambridge Greensand. 

 Five carapaces of B. Harrisiana were found at Swaffham. 



Bairdia Harrisiana, Jones, var. amplior, Jones and Hinde. 



Bairdia Harrisiana, Jones, var. amplior, Jones and Hinde, 1890, Suppl. 

 Mon. Cret. Entom. pp. 8, 9, pi. ii. fig. 57, pi. iv. fig. 4. 



This variety was obtained by the above authors from the 

 Chalk of Kent, and it is now represented for the first time 

 from the Cambridge Greensand by two left valves, found at 

 Swaffham. 



Macrocypris, G. S. Brady, 1867. 



Macrocypris siliqua, Jones. 



Macrocypris siliqua, Jones and Hinde, 1890, Suppl. Mon. Cret. Entom. 

 p. 9, pi. ii. figs. 38-41. 



We have hitherto known this species to occur in various 

 beds of the Upper Cretaceous from the Upper Greensand to 

 the Upper Chalk, as well as in the Eocene of Transylvania ; 

 but it has not occurred before in the beds now under notice, 

 nor does it appear in the Gault. 



One carapace of M. siliqua was found at Swaffham. 



Macrocypris simplex, sp. n. (Figs. 1 a-c.) 



Carapace as seen from the side elongated, siliquose ; height 

 greatest just above the middle j ventral border incurved 



