Vol. 50.] ME. F. CHAPMAN ON THE BAKGATE BEDS OF 8UEEEY. 721 



123. Discoebina Vilaedeboana (d'Orbigny). 



Rosalind Vilardeboana, d'Orbigny, ' Foram. Amer. Herid.' 1839, 

 p. 44, pi. vi. figs. 13-15. 



Discorhina Vilardeboana, Brady, 'Challenger' Rep. vol. ix. (1884) 

 p. 645, pi. lxxxvi. figs. 9, 12 ; pi. lxxxviii. fig. 2. 



One specimen of this shallow-water species was found in the 

 Pebble-beds, Littleton. 



124. Discoeblna aeaxtcana (d'Orbigny). 



Bosalina araucana, d'Orbigny, ' Foram. Amer. Merid.' 1839, 

 p. 44, pi. vi. figs. 16-18. 



Discorhina araucana, Brady, ' Challenger ' Rep. vol. ix. (1884) 

 p. 645, pi. lxxxvi. figs. 10, 11. 



Thirteen specimens of the above species, which is a shallow-water 

 form, were found in the Pebble-beds, Littleton ; and one in the 

 Pebble-beds, Halfpenny Lane, Chilworth. 1 



TErrxCATUiiNA, d'Orbigny. 



125. Tettncatoxina. lobattjxa (Walker & Jacob). 



Nautilus lobatidus, Walker & .Jacob, Adams's Essays, Kan- 

 macher's ed. (1798) p. 642, pi. xiv. fig. 36. 



Truncatidina lobatula, Brady, ' Challenger ' Rep. vol. ix. (1884) 

 p. 660, pi. xcii. fig. 10 ; pi. xciii. figs. 1, 4, 5 ; pi. cxv. figs. 4, 5. 



Two specimens of this widely distributed species were found in 

 the Pebble-beds, Littleton. 



126. Teuncatulina vaeiabilis, d'Orbigny. 



Truncatulina variabilis, d'Orbigny, Ann. Sci. Nat. vol. vii. (1826) 

 p. 279, no. 8; Brady, 'Challenger' Rep. vol. ix. (1884) p. 661, 

 pi. xciii. figs. 6, 7. 



This form has been noted from the Chalk of Taplow, and from 

 various Tertiary formations. 



Four specimens from the Pebble-beds, Littleton. 



127. TeTOTCATTTLINA falcata, Reuss. (PI. XXXIV. fig. 15 a, b, c.) 



Truncatulina falcata, Reuss, Sitzungsb. Akad. Wissensch. Wien, 

 vol. lix. (1869) pt. i. p. 461, pi. ii. fig. 1. 



This species was described by Reuss from the Oligocene Beds 

 of Gaas in the South of France, in which deposit it appears to be 

 very rare. 



T. falcata is by far the most abundant species of foraminifera in 

 the Bargate Beds of Surrey, and the specimens, moreover, agree very 

 nearly with the original description of the test. There are, how- 

 ever, these unimportant differences between the Oligocene and the 



1 The specimens of D. araucana, and also some of D. rugosa, exhibit a 

 tendency to become elongate in the plane of their discoidal growth, somewhat 

 after the manner of Truncatulina variabilis. 



