PLATE 25 



Figs. la, b, c. Pseudomelania (Oonia) aitkeni sp. nov. Middle-Upper Kimmeridgian. 

 Mandawa-Namakongoro stream, 1 mile W. of Mandawa, Tanganyika. Holotype, 

 GG.10318 : a, x 1 ; b, apertural view, x 2 ; c, abapertural view, x 2 . . p. 151 



Figs. 2a, b, c. Pseudomelania {Oonia) conica (Morris & Lycett). Bathonian (?). 2 

 miles W. of Tengeni, Tanganyika. 00.10463 : a, X 1 ; b, apertural view, x 2 ; 

 c, abapertural view, x 2 . . . . . . . . . . .p. 150 



Figs. 3a, b. Zygopleura mandawaensis sp. nov. Bajocian (?). Depth 58-60 feet, 

 Mandawa well no. 6, Tanganyika. Paratype, GG. 10287 : «, X 1 ; ft, X 4 . . p. 154 



Figs. 4a, b. Coelostylina mandawaensis sp. nov. Bajocian (?), Pindiro Shales. 

 Lihimaliao creek, Mandawa area, Tanganyika. Paratype, GG. 10286, showing aperture : 



a, x 1 ; b, x 3 p. 153 



Figs. 5a, b. Same species and formation. Near site of Mandawa well no. 1, Tanganyika. 



Holotype, GG. 10283 : «, x 1 ; ft, x 3 . . . . . . . . p. 153 



Figs. 6a, b. Same species, formation and locality. Paratype, GG. 10285 : a, x 1 ; 



ft. X 3 p. 153 



Figs, ya, b. Same species, formation and locality. Paratype, GG. 10284 : a, x 1 ; 



b, X 3 p. 153 



Fig. 8. Bourguetia saemanni (Oppel). Upper Oxfordian, Seir Limestones. Dusse, 



1 \ miles S.E. of Rahmu, N.E. Kenya. G.76404, x 1 . . . . . . p. 152 



Fig. 9. Same species. Upper Oxfordian. E. margin of Makoko plain, Bagamoyo 



hinterland, Tanganyika. GG.2182, x 1 . . . . . . .p. 152 



Fig. 10. Pseudomelania (Rhabdoconcha) wilderriensis sp. nov. Upper Oxfordian, Seir 



Limestones. Wilderri hill, 11 miles S.S.W. of Rahmu, N.E. Kenya. Holotype, G. 76414, 



XI p. 151 



Fig. 11. Zygopleura mandawaensis sp. nov. Bajocian (?), Pindiro Shales. Lihimaliao 



creek, Mandawa area, Tanganyika. Holotype, GG. 10465, X 3 . . . .p. 154 



