FROM TANGANYIKA AND KENYA 173 



Material. Several specimens (nos. G. 70517-18, G. 76375-76, G. 76389) preserved 

 in hard limestone. 



Localities and horizon. Melka Dakacha, 1 mile W. of Melka Dakacha, and 1 

 mile S.S.W. of Melka Dakacha, N.E. Kenya ; Upper Kimmeridgian, Dakacha Lime- 

 stones. 



Remarks. These specimens agree well with European ones in the angle of their 

 spire and in their very feebly convex, non-gradate whorls. The largest one was 15 

 cm. or more high when complete. Axial sections show the broad umbilicus and a 

 single, very strong internal fold, projecting from the upper wall of the whorls. In 

 Europe this species ranges from the Lower Kimmeridgian to the Upper Kimmerid- 

 gian and probably higher. 



Order TECTIBRANCHA Cuvier 



Superfamily BULLACEA 



Family ACTEONIDAE d'Orbigny 1842 



Genus ACT EO NINA d'Orbigny 1850 



Subgenus STRIACTAEONINA Cossmann 1895 



Acteonina {Striactaeonina) supraliasica sp. nov. 

 PI. 29, figs. 4«, b, c 



Diagnosis. Of medium size for the subgenus (height of largest specimen c. 15 

 mm.), with a relatively high and narrow, cylindrical last whorl and an acute, gradate- 

 conical spire, the height of which is about one-quarter of that of the shell. Whorls 

 with a steep, flattened ramp which forms an angle of about 60 ° with the horizontal 

 and a subvertical outer face, of which only a narrow strip is exposed on the spire. The 

 outline of the last whorl is broadly convex where it merges abapically into the steeply 

 sloping base. Outer face and base ornamented with unevenly spaced, linear spiral 

 grooves. Aperture very narrow adapically ; outer lip not preserved intact ; inner 

 lip simple, with a thin, narrowly spread, distinctly margined coating of callus. 



Holotype and paratypes. Nos. GG.10271 and GG.10272-74 respectively, four 

 specimens in all. 



Locality and horizon. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ; 

 Upper Lias, Toarcian, Didimtu Beds. 



Remarks. The specimens are rather eroded and it is not possible to see if the 

 spiral groove commonly found just below the ramp in species of Striactaeonina is 

 present. The general form of the shell resembles that of some species of Cylindrites, 

 but the presence of spiral ornament and the absence of folds low on the columellar lip 

 distinguish it from that genus. 



