714 MB. P. CHAPMAN ON THE BARGATE BEDS OF SURREY. [Nov. 1 894, 



91. Cristellaria rotulata (Lamarck). 



Lenticulites rotulata, Lamarck, Ann. Museum, vol. v. (1804) 

 p. 188, no. 3 ; Tab. Encycl. Meth. pi. cccclxvi. fig. 5. 



Cristellaria rotulata, Brady, ' Challenger ' Rep. vol. ix. (1884) 

 p. 547, pi. lxix. fig. 13 a, b. 



This species makes its first appearance in beds of Ordovician age 

 (Ulrich), and is common in most fossiliferous deposits up to the 

 present time. As a recent form it occurs in shallow-water deposits 

 and also in those down to a depth of 2200 fathoms (Brady). 



Twelve specimens from the Pebble-beds, Littleton, and two from 

 the Pebble-beds, Halfpenny Lane. 



92. Cristellaria cultrata (Montfort). 



Robulus cultratus, Montfort, ' Conchyl. System.' vol. i. (1808) 

 p. 214, 54 e genre. 



Cristellaria cultrata, Brady, ' Challenger ' Bep. vol. ix. (1884) 

 p. 550, pi. lxx. figs. 4-6. 



This form is first met with in beds of Liassic age, and it is also 

 fairly common in Cretaceous and Tertiary strata. As a recent 

 organism it affects deeper water than the preceding species. 



Nine specimens from the Pebble-beds, Littleton, and two from 

 the Pebble-beds, Halfpenny Lane. 



93. Cristellaria gibba, d'Orbigny. 



C.gibba, d'Orbigny, 'Foram. Cuba,' 1839, p. 63, pi. vii. figs. 20, 21. 



C. pulcliella, Reuss, Sitzungsb. Akad. Wissensch. Wien, vol. xlvi. 

 (1862) p. 71, pi. viii. fig. 1. 



The fossil forms recorded by Beuss were from the Upper Hils-Thon 

 and the Minimus-Thoa of North Germany. As a recent form it is 

 found in soundings down to 500 fathoms (Brady). 



Eight specimens from the Pebble-beds, Littleton, and one from 

 the Pebble-beds in Halfpenny Lane. 



94. Cristellaria convergens, Bornemann. 



C. convergens, Bornemann, Zeitschr. deutsch. geol. Gesellsch. 

 vol. vii. (1855) p. 327, pi. xiii. figs. 16, 17. 



As a fossil the above species has been recorded from Tertiary 

 strata. It is also found as a recent form, usually in deep water. 



Two specimens from the Pebble-beds, Littleton. 



95. Cristellaria promintjla, Beuss. 



C. prominula, Beuss, Zeitschr. deutsch. geol. GeseUsch. vol. vii. 

 (1855) p. 271, pi. ix. fig. 3 a, b. 



One specimen of this Cretaceous species was found in the Pebble- 

 beds, Littleton. 



96. Cristellaria megalopolitana (Beuss). 



Robulina megalopolitana, Reuss, Zeitschr. deutsch. geol. Gesellsch. 

 vol. vii. (L855) p. 272, pi. ix. fig. 5 a, b. 



