FROM TANGANYIKA AND KENYA 69 



Limestones. 3 miles N.E. of Melka Dakacha, N.E. Kenya ; Upper Kimmeridgian, 

 Dakacha Limestones. i£ miles E. of Kidugallo Station, Central Railway, Tangan- 

 yika ; Bajocian, Station Beds. 



1821 



1857 

 1930 



1938 

 1952 



Lopha eruca (Defrance) 



Ostrea eruca Defrance : 31. 



Ostrea hastellata [rastellata] Quenstedt : 750, pi. 91, figs. 26, 27. 



Arctostrea hastellata (?non Quenstedt ; de Loriol) ; Weir : 85, pi. 9, fig. 4. 



Lopha krumbecki Weir : 45, pi. 3, fig. 7. 



Lopha eruca (Defrance) ; Cox : 103, pi. 11, figs. 1-7. 



Material. One internal mould (no. LL.35101), ex B.P. Coll. 



Locality and horizon. \ mile from Msata on road to Bagamoyo, Tanganyika ; 

 Callovian or Oxfordian (in friable brown sandstone). 



Remarks. Although merely an internal mould, this specimen undoubtedly be- 

 longs to Defrance's species, the full synonymy of which is given in my paper cited 

 above. There is little doubt that the specimens from Kenya recorded by Weir 

 (1930, 1938) belong to this species. 



Lopha cf. intricata (Contejean) 

 PI. 9, figs. 8a, b 

 i860. Cf. Ostrea intricata Contejean : 323, pi. 25, figs. 6-8. 



Material. One specimen (no. L. 83899). 



Locality and horizon. b\ miles S.S.W. of Rahmu, N.E. Kenya ; Oxfordian, 

 Rahmu Shales. 



Remarks. This is a tall, oval, slightly oblique and lunate, weakly inflated speci- 

 men, 44 mm. in height and 28 mm. broad, with a large attachment area from which 

 the walls of the lower valve, folded into plications of small amplitude, rise vertically 

 to the commissure. The upper valve, which has an irregular surface, is weakly con- 

 vex and also plicated at its margins. Except that its lower valve is not quite so deep, 

 this specimen agrees well with Contejean's figure of the holotype of Ostrea intricata, 

 a specimen of Lower Kimmeridgian age. In 0. vallata Etallon (de Loriol 18946 : 75, 

 pi. 9, figs. 5, 6), from the Swiss Oxfordian, the plications are sharper and more num- 

 erous. It is difficult to say whether or not these specimens are merely examples of 

 better-known species of Lopha in which the development of plications on both 

 valves has been restricted by an unusually large attachment-area. 



Lopha solitaria (J. de C. Sowerby) 

 PI. 9, fig. 4 



1824a. Ostrea solitaria J. de C. Sowerby : 105, pi. 468, fig. 1. 



1933a. Lopha solitaria (Sowerby) ; Arkell : 185, pi. 22, fig. 4 ; pi. 23, figs. 5-7. 



1935a. Lopha solitaria (Sowerby) ; Cox : 171, pi. 17, figs. 9-12. 



i960. Lopha solitaria (Sowerby) ; Joubert, pi. 9, figs. 2a-c. 



