200 



Mr. R. B. Newton on Fussil MoUusca d;c, 



views ot" the organism, although there are fragmentary pieces 

 yielding sufficient of the median plane aspect to show ihe 

 rectangular nature of the chambers. This rectangular cha- 

 racter, as seen on the median plane, permits of a true generic 

 determination in favour of Orthophragmina, as opposed to 

 Lepidocyclina with rounded or hexagonal chambers, which is 

 of Lower Tertiary age, and ranges from Eocene to Oligocene 

 (Priabonian) times. Judging by the excellent figures of 

 Giimbel and also of Schlumberger, we may regard these 

 specimens as Michelin's pratti, which ranges from Lutetian 

 to Priabonian* and is found at Biarritz t, Kressenberg, 

 Italy, &c. For present purposes, therefore, it may be stated 

 that the limestone from Soutliern Nigeria belongs to the 

 Eocene series, and either to the Lutetian, Bartonian, or 

 Priabonian division of that formation. 



A. Orthophraf/mina pratti, fioiu La<--oa. showing vertical sections. 



B. Ditto, ditto, equatorial section, sliowing rectaugiiiar character of the 



chambers, 



C. Ditto, from Biarritz (for comparison). 



Loc'ilittj. Lagos Province of Southern Nigeria, about U 

 miles from a spot localized as 6° 38' 30" N. lat., and 4° 3?' 00" 

 E. long., where tiie bitumen-bearing beds occur with tiic 

 marine Mollasca. 



* Oppenheim, "Die Priahonaschichten uud ihre Fauna," Palaeonto- 

 graphica, 1900, vol. xlvii. p. 44. _ ,. ^. ■ „ a..i. 



t Prever, " 1 terreni Nummulitici di Gassmo et di Biamtz, Atti It. 

 Accad. Sci.Toriuo, 1905, vol. xli. pp. 10-12. 



