FROM TANGANYIKA AND KENYA 71 



obscured although their interiors are well exposed.) Adductor scar large. Margins 

 of both valves with rounded, unevenly spaced plications which scarcely extend on 

 surface of shell even where this is not obscured by adherent specimens. In one 

 specimen which appears to be a left valve (although this is not altogether certain as 

 its dorsal half is broken away) the somewhat eroded surface bears unevenly arranged, 

 discontinuous pustules and superficial ribs. 



Holotype and paratypes. Holotype, no. L. 54855 ; four paratypes, of which 

 L. 54856 and L. 54858 are figured. 



Localities and horizon. Kindope (type-locality), and N. of Kinjele, both near 

 Tendaguru, Tanganyika ; Upper Kimmeridgian, Nerinella Bed. 



Remarks. This form, with its weak plications confined to the margins, appears 

 to lie on the border-line between Ostrea and Lopha. It is much larger but relatively 

 less inflated than Lopha intricata (Contejean), referred to above, and also differs in 

 its angular outline. 



Lopha hennigi (Dietrich) 

 *933- Alectryonia hennigi Dietrich : 70, pi. 10, figs. 144, 145. 



Material. Several specimens. 



Localities and horizons. Mtapaia road and Kipande path, near Tendaguru, 

 Tanganyika ; Upper Kimmeridgian, " Trigonia smeei " Bed. Kindope, near 

 Tendaguru, Tanganyika ; Upper Kimmeridgian, Nerinella Bed. 



Remarks. This is a large, thick-shelled oyster with strong, angular, unequal 

 plications, bifurcating in places. It is closely related to the widespread Jurassic 

 species L. marshii (J. Sowerby), which occurs at lower horizons in East Africa, but 

 is represented only by poor and somewhat doubtful specimens in the material 

 studied. 



Genus LIOSTREA Douville 1904 

 Liostrea dubiensis (Contejean) 



i860. Ostrea dubiensis Contejean : 320, pi. 21, figs. 4-1 1. 



I935 a - Ostrea (Liostrea) dubiensis Contejean ; Cox : 171, pi. 17, figs. 4, 5. 



Material. Numerous specimens. 



Localities and horizons, i mile and 2 miles W. of Magindu Station, Central 

 Railway, Tanganyika ; about Bathonian. 1 mile N. of Asaharbito, N.E. Kenya ; 

 Bathonian [? or Callovian], Asaharbito Beds. Ogar Wein and Golberobe hills, N.E. 

 Kenya ; Oxfordian, Golberobe Beds. Dusse, 1^ miles S.E. of Rahmu, N.E. Kenya ; 

 Upper Oxfordian, Seir Limestones. Kiwato-Mkange track, 5 miles S.S.E. of Mkange, 

 Bagamoyo hinterland, Tanganyika ; Oxfordian or Kimmeridgian. Tingutitinguti 

 creek and Kindope, both near Tendaguru, Tanganyika ; Upper Kimmeridgian, 

 " Trigonia smeei " and Nerinella Beds. 



