FROM TANGANYIKA AND KENYA 23 



Chlamys curvivarians (Dietrich) 



Lima (Plagiostoma) sublaeviuscula Krumbeck 



Ctenostreon proboscideum (J. Sowerby) 



Lopha gregarea (J. Sowerby) 



Rutitrigonia stefaninii (Venzo) 



Mactromya quadrata (Roemer) 



Quenstedtia jouberti sp. nov. 



Ceratomya excentrica (Roemer) 



Pholadomya hemicardia Roemer 



Harpagodes thirriae (Contejean) 



Globularia hemisphaerica (Roemer) 



Globularia hennigi sp. nov. 



Trochalia depressa (Voltz) 

 The assemblage listed above includes none of the characteristic trigoniids or other 

 elements of the Tendagura fauna. The occurrence of such species as Modiolus 

 virgulinus and Harpagodes thirriae, found apparently in the top bed of the Dakacha 

 Limestones (Joubert 1960 : 27), suggests, from the known European occurrences of 

 these species, that this bed is Kimmeridgian in age (even in the more restricted 

 sense) and not later. The presence of Rutitrigonia stefaninii, however, serves as a 

 link between this fauna and that of the beds at Cud Finagubi, discussed a little 

 later, and is interesting as constituting the earliest known occurrence of Rutitrigonia. 

 If the East African Kimmeridgian assemblages listed above are considered as a 

 whole, it will be seen that, while, like those from lower horizons, they include a large 

 number of species found in the Jurassic of Europe, they have an Indian element 

 which is rather more pronounced than in the earlier faunas. Affinity with the Indian 

 fauna is particularly marked among the trigoniids, as seen by the abundance (in 

 southern Tanganyika) of Indotrigonia and by the presence there of Opisthotrigonia. 

 Other forms common to the two areas but not found in Europe are Astarte sowerby ana 

 Holdhaus and Stegoconcha gmuelleri (Krenkel). Indogrammatodon continues 

 to be an important element of the African fauna, although the actual species of 

 Kimmeridgian age here recorded are distinct from those found in India. The only 

 known post-Liassic occurrence of the genus Hippopodium is in these East African 

 beds, while it is interesting to find in the Upper Jurassic of this region the remarkable 

 astartid genus Seebachia, otherwise known only from South Africa, where it occurs 

 in the Neocomian. Quite a number of Kimmeridgian species, some here described 

 as new and others described in earlier monographs by Miiller, Dietrich, Hennig and 

 Aitken, have so far been found only in East Africa. 



In the extreme north-east of Kenya a series of beds is developed the age of which 

 has given rise to some controversy. Termed by Dixey (1948 : 84) the Mandera 

 Series, these beds have been described by Joubert (i960 : 31-39), who cites 

 evidence from N.E. of Melka Dakacha that they succeed the Dakacha Limestones 

 conformably. Some 40 ft. from the base of this series is a fossiliferous deposit 

 (the basal bed of the subdivision termed by Joubert the Gudediye Beds) 

 yielding the two bivalve species here described as Tancredia manderaensis sp. nov. 



