4<> JURASSIC BIVALVIA AND GASTROPODA 



Material. One specimen (no. LL. 35095). 



Locality and horizon. Near site of Mandawa well no. 1, Tanganyika ; Bajo- 

 cian (?), Pindiro Shales. 



Remarks. The specimen is a crushed right valve with a sub-median carina on the 

 dorsal side of which are about 12 radial riblets ; the ventral side bears well-marked 

 growth-folds but is devoid of radial ornament. In having its radial ornament con- 

 fined to the dorsal half of the surface the specimen resembles the original figure of the 

 species, which represents a specimen from the Inferior Oolite of Holtensen, northern 

 Germany ; its riblets, however, are more numerous than in the German specimen. 

 In the specimens from the Upper Bajocian of Switzerland figured by Greppin radial 

 riblets are present also on the ventral side of the median carina. 



Pinna mitis Phillips 



1829. Pinna mitis Phillips : 137, pi. 5, lig. 7. 



1883. Pinna mitis Phil. ; Lahusen : 27, pi. 2, fig. 12. 



1910. Pinna sp. ; Dacque : 29, pi. 5, fig. 4. 



1924. Pinna mitis Ziet. ; Hennig : 71, pi. 2, fig. 7. 



1934. Pinna mitis Phil. ; Stoll : 19, pi. 2, fig. 9. 



Material. Several specimens. 



Locality and horizon. 6\ miles N.E. of Pande (village on Mkwaja-Mkata road) 

 and z\ miles N. of Msangasi stream, N.E. Tanganyika ; Callovian. 



Remarks. The specimens, the largest of which were about 60 mm. long when 

 complete, are preserved in a hard sandstone and, when an attempt is made to extract 

 them, usually break in such a manner that part of the wall of the shell adheres to 

 each counterpart. Sufficient of their ornament can, however, be seen to show that 

 it agrees with that of Pinna mitis, already recognized by Hennig (1924) in the Callo- 

 vian of Tanganyika. 



Pinna constantini de Loriol 



1875. Pinna constantini de Loriol : 161, pi. 19, fig. 2. 



1897. Pinna constantini de Loriol ; Futterer : 596, pi. 20, figs. 5, 5a. 



1933. Pinna cf. constantini de Loriol ; Dietrich : 60, pi. 8, figs. 131-134. 



Material. Several specimens. 



Localities and horizons. Valley and scarp at Kindope, N.N.W. of Tendaguru, 

 Tanganyika ; Upper Kimmeridgian, " Trigonia smeei " and Nerinella Beds. 



Remarks. The specimens from East Africa agree so well with de Loriol's illustra- 

 tion of the type specimen from the " Portlandien moyen " of France, that there 

 seems no need to qualify the identification. The number of ribs on the dorsal side 

 of the median carina of each valve is 5-7, while the number below the carina in- 

 creases during growth to 6 or more, the extreme ventral part of the surface bearing 

 only growth-folds. 



