150 Annals of the South African Museum. 



Eiver, in association with the characteristic Trigonia of the Marine 

 Beds. In 1905 Mr. Eogers found this species in the cliff on Buck 

 Kraal, Sunday's Eiver (128h). 



Remarks. Cyprina rugulosa, in its inflated character, the position 

 of the umbones, and the wrinkled surface, bears no slight resem- 

 blance to C. regularis d'Orb.,* from the lower Gault of Europe ; it 

 differs chiefly in the manner in which the upper margin slopes away 

 posteriorly into the posterior margin. The European form has 

 greater relative height at its posterior end, with an accompanying 

 aspect of truncation. 



Some individuals of C. rugulosa, in which the shell attains a rather 

 greater height in proportion to length than in the majority of 

 specimens I have examined, approach somewhat closely in form to 

 a Cyprina recorded by Dacqu6 from strata of supposed Aptian age 

 in Somaliland ; I but C. rugulosa is less strongly inflated, and 

 most examples are further distinguished by their rough surface 

 markings. 



CYPRINA BOBCHEEDSI Tate. 



1867. Cyprina borcherdsi E. Tate, Quart. Journ. Geol. Soc., vol. xxiii., 

 p. 161, pi. viii., fig. 2. 



Occurrence. Found in the railway cutting between milestones 

 241 24J on the line from Uitenhage to Graaff-Eeinet, about three 

 miles from Uitenhage (313). The specimens described by Tate were 

 also from the Zwartkop's Eiver. 



A specimen obtained by Mr. Eogers from the left side of the Coega 

 Valley, half a mile down from the railway (467g), must also be 

 referred to the same species. 



Eemarks. Tate's type-specimen is unfortunately inaccurately 

 figured, and is represented as considerably more elongated than it 

 really is. It measures 42 mm. in greatest length and 31 mm. in 

 height, while the corresponding measurements of the illustration in 

 Tate's paper are 47 mm. and 27 mm. respectively. The greatest 

 depth (convexity) of this type-specimen (a single valve) is about 

 10 mm. A specimen obtained by Messrs. Eogers and Schwarz is an 

 immature individual measuring 17 mm. in height ; it is imperfect 

 anteriorly, and consequently has the aspect of being more equilateral 

 than Tate's shell, though a careful comparison leaves no doubt about 

 its identity. 



* d'Orbigny (3), p. 100, pi. 272, figs. 3-6 (1844) ; Pictet and Campiche (1), 

 3 e Partie, p. 224, pi. cxv., figs. 1, 2 (1865). 

 f Dacqu4 (1), p. 16, Taf. ii., fig. 9. 



