PLATE 24 



Figs. 1a, b, c. Chrysostoma staffi Dietrich. Upper Kimmeridgian. Tapaira trail, S. 

 of Tendaguru, Tanganyika. G. 48567 : a, x 1 ; b, apertural view, x 2 ; c, abapertural 

 view, x 2 ............. p. 142 



Figs, za, b. Ataphrus aff. acmon (d'Orbigny). Bajocian. Kidugallo, Tanganyika. 

 G. 26204 : *i X 1 ; 1, X 3 . • • • • • • . . . p. 143 



Figs. $a, b. Chartronella mitoleensis sp. nov. Upper Kimmeridgian. Mpilepile 

 stream, about 1 mile N.E. of Mitole, Tanganyika. Holotype, GG.10313 : a, apertural 

 view ; b, abapertural view, both x 1 . . . . . . . . p. 145 



Figs. 4a, b. Lissochilus stremmei Dietrich. Upper Kimmeridgian. \\ miles N.W. of 

 Mandawa, Tanganyika. GG.10315 : a, apertural view ; b, abapertural view, both x 1 p. 145 



Figs. 5a, b, c, d. Trochopsidea africana sp. nov. Upper Lias, Toarcian. Didimtu hill, 

 2 miles S. of Bur Mayo, N.E. Kenya. Holotype, GG. 10258 : a, x 1 ; b, apertural view, 

 X 3 ; c, abapertural view, X 3 ; d, base, X 3 . . . . . . .p. 143 



Figs. 6a, b. Pseudomelania (Oonia) dietrichi sp. nov. Upper Kimmeridgian. " Trigonia 

 smeei " Bed. Tingutitinguti creek, Tendaguru, Tanganyika. Holotype, G. 48028 : 

 a, apertural view ; b, abapertural view, both x 1 . . . . . . p. 150 



Figs, ya, b. Neritoma (Neridomns) aff. gea (d'Orbigny). S. of Tarawanda, 11 miles 

 S.E. of Lugoba, Tanganyika. G.61310 : a, x 1 ; b, x 2 . . . . . p. 144 



Figs. 8a, b. Cirrus mazarasensis sp. nov. Bajocian (?), Mazeras Sandstones. Ribe, 

 9 miles N.E. of Mazeras, Kenya. Holotype, GG.6524, " squeeze " from natural mould : 

 a, x 1 ; b, x 2-5 . . . . . . . . . . . . p. 146 



Figs, ga, b. Hamusina Ihompsoni sp. nov. Upper Lias, Toarcian. Didimtu hill, 

 2 miles S. of Bur Mayo, N.E. Kenya. Holotype, GG. 10263 ■ a, x 1 ; b, x 3 . p. 146 



Fig. 10. Pseudomelania aspasia (d'Orbigny). Callovian. Nchia stream, 2 miles 

 W. N.W. of Mandawa, Tanganyika. GG.10317, x 1 . . . . .p. 147 



Figs. 11a, b, c. Pseudomelania dusseensis sp. nov. Upper Oxfordian, Seir Limestones. 

 Dusse, i£ miles S.E. of Rahmu, N.E. Kenya. Holotype, G. 76399 ; a, x 1 ; b, aper- 

 tural view, x 3*7 ; c, abapertural view, x 37 . . . . . .p. 148 



Fig. 12. Pseudomelania vittata (Phillips). Middle-Upper Kimmeridgian. 1 mile 

 X. of Manyuli, Tanganyika. GG.10316, X 1 . . . . . . .p. 148 



