io6 JURASSIC BIVALVIA AND GASTROPODA 



Material. One specimen (no. L. 92194). 



Locality and horizon. Hereri river crossing, 3 miles S. of Melka Kunha, N.E. 

 Kenya ; Kimmeridgian, Hereri Shales. 



Remarks. Dietrich founded the subgenus Tendagurium for equilateral Mesozoic 

 Cardiidae lacking radial ornament. The question whether the type-species, Cardium 

 propebanneianum, is specifically distinct from C. bannesianum is discussed below. 

 There is no doubt that the two forms are closely related. In Europe this species 

 appears to be confined to the Kimmeridgian. 



Protocardia (Tendagurium) propebanneiana (Dietrich) 



PI. 16, fig. 6 



x 933- Cardium [Tendagurium) propebanneianum Dietrich : 50, pi. 6, figs. 92, 93. 



Material. About 10 specimens. 



Locality and horizon. Tingutitinguti creek, Tendaguru, Tanganyika ; Upper 

 Kimmeridgian, " Trigonia smeei " Bed. 



Remarks. Dietrich, when describing this species, discussed its possible identity 

 with Cardium bannesianum Contejean, and concluded that it differs in its better 

 developed posterior ridge and its less strongly convex pallial margin. These differ- 

 ences, however, are not strongly marked. Dietrich mentions a specimen of C. pro- 

 pebanneianum 80 mm. long, and the length of the largest of the specimens now 

 recorded is 70 mm. These measurements are not greatly in excess of the maximum 

 length of 65 mm. given by de Loriol for C. bannesianum. Dietrich mentions and 

 illustrates a distinct pallial sinus in C. propebanneianum, whereas there is no sinus in 

 C. bannesianum, but his figure has evidently been retouched to make the sinus 

 obvious. Some of the specimens now recorded are internal moulds, but the pallial 

 line is not clearly seen in any of them. The posterior adductor scar has, however, a 

 well-marked anterior angle, and if this marks the point where the pallial line met the 

 scar it is possible that a sinus may have been present and that the specific separation 

 from C. bannesianum is justified. 



Superfamily ISOCARDIACEA [GLOSSACEA] 



Family CERATOMYOPSIDAE Cox 1964 



Genus CERATOMYOPSIS Cossmann 1915 



Ceratomyopsis basochiana (Defrance) 

 PI. 17, figs. 7, 8a, b 



1822. Isocardia basochiana Defrance : 18. 



18226. Isocardia basochiana Defrance ; J. Sowerby, Part 7, " Isocardia " pi., fig. 4. 



1850a. Ceromya sarthacensis d'Orbigny : 336. 



1900. Isocardia striata d'Orbigny ; Miiller : 534, pi. 18, figs. \a, b (non d'Orbigny). 



