FROM TANGANYIKA AND KENYA 89 



Material. Four specimens (nos. LL. 16837-40). 



Locality and horizon. Usigiwa river, 6 miles W.S.W. of Kiwangwa, Baga- 

 moyo hinterland, Tanganyika ; Upper Oxfordian. 



Remarks. The length of the largest specimen referred to this species is 72 mm. 

 The shell is ovate, with the height equal to about three-quarters of the length, and 

 is strongly inequilateral and of moderate and even convexity. The umbo is slightly 

 obtuse and not quite terminal. The postero-dorsal outline is of moderate convexity, 

 rising at first to a level slightly above that of the umbo, and then sloping down to 

 form a rounded-off, obtuse angle with the slightly oblique and flattened posterior 

 margin ; the antero-dorsal outline is scarcely excavated. The ventral and antero- 

 ventral margins are of strong convexity. The lunule is shallow and there is no 

 escutcheon. The surface bears concentric undulations, which are regular in early 

 stages of growth, but later become very irregular. 



The African specimens do not appear to differ in any features of importance from 

 A. episcopalis which occurs typically in the " Middle Oxfordian " of the Bernese 

 Jura. Of the other species now recorded from East Africa, A. muelleri Dacque is 

 more trigonal in outline. A. subobovata Dietrich is more rounded posteriorly and 

 less elongate, A . recki Dietrich has a more strongly convex postero-dorsal outline, 

 and A. mitoleensis sp. nov. is more elongate and tapers more towards its posterior 

 end. 



Astarte huralensis Stefanini 

 PI. 15. ng. 1 



1939. Astarte huralensis Stefanini : 234, pi. 24, figs. 19, loa-c. 

 i960. Astarte sp. nov. ; Joubert, pi. 9, figs. 4a, b. 



Material. Numerous specimens (nos. L. 92123, L. 92236-39), preserved on the 

 surface of blocks of limestone. 



Locality and horizon. Dusse, i^ miles S.E. of Rahmu, N.E. Kenya ; Upper 

 Oxfordian, Seir Limestones. 



Remarks. The specimens now recorded agree well in size and ornament with 

 Stefanini's figures, which do not, unfortunately, show the outline of the shell very 

 clearly. The Kenya specimens are up to about 9 mm. in length, rectangularly ovate 

 to subtrigonal, with the length slightly exceeding the height, and not strongly in- 

 flated. The umbo, which is obtusely angular and not incurved, is not quite terminal, 

 the anterior margin of the shell projecting slightly beyond it. The dorsal margin is 

 convex, meeting the nearly straight and vertical posterior margin in a rounded-off, 

 obtuse angle. The ventral margin is strongly convex and the antero-dorsal outline 

 is moderately excavated below the beak. The ornament consists of relatively wide- 

 spaced, obtusely angular concentric ridges, the crests of which are about i-8 mm. 

 apart ; no subordinate threads are present. 



The most closely comparable European species appears to be Astarte cingulata 

 Contejean (i860 : 267, pi. 11, figs. 5-10), from the Kimmeridgian, in which the out- 

 line of the shell is more trigonal. A. huralensis was described originally from the 

 " Oolitico medio " (? Oxfordian) of southern Somalia. 



