32 Annals of the South African Museum. 



fact, compares more satisfactorily with some of the Cretaceous 

 forms. 



The comparison of Pecten rubidgeanus with P. subspinosus Schloth. 

 cannot be pronounced at all fortunate, while we shall find that Lima 

 obliquissima shows a closer agreement of characters with Cretaceous 

 and later forms than with the European Jurassic shells cited by 

 Tate. 



Placunopsis subjurensis Tate, which was compared with P. jurensis 

 Boern., may perhaps be an Anomia, and in some respects closely 

 resembles A. pseudoradiata d'Orb., * from the Aptian. Placunopsis 

 imbricata Tate is compared in the table with P. substriata Lye., 

 from the Oolites. P. scmistriata (Bean) was probably the English 

 shell with which it was intended to institute comparison, since this 

 name alone is mentioned in Tate's description on page 154 of his 

 paper. P. imbricata, however, is without radial ornamentation, but 

 is characterised by well-spaced concentric ridges which recall the 

 similar ornamentation of Anomia neocomiensis d'Orb., t though 

 occurring in less emphasised form. The illustration of P. imbricata 

 gives a very poor idea of the shell, but an examination of the 

 specimen dispels the notion of a close comparison with known 

 Jurassic forms. 



Trigonia cassiope Tate is not to be united with any known Jurassic 

 costate Trigonia, and was accordingly renamed T. tatei by Neumayr. 

 It is well distinguished by the elongated escutcheon, the very 

 delicate marginal carina, and the fine character of the ornamentation 

 on the area and escutcheon. Trigonia goldfussi Tate is an immature 

 shell, and in all probability illustrates the youthful stage of one of 

 the large and robustly ornamented Pseudo-quadratae which form 

 such a striking feature in the Uitenhage fauna. It certainly does 

 not represent either Trigonia goldfussi Agassiz or T. painei Lye. 

 ( = T. goldfussi Morr. and Lye.), with which it was identified. Tate 

 himself, on page 159 of his paper, said : " Hereafter, however, it 

 may be found to be the young of a distinct species." It is therefore 

 the more regrettable that the error of quoting this European Jurassic 

 shell from the Uitenhage beds should have continued to be perpe- 

 trated. Stow I repeatedly used the name " T. goldfussi " in his 

 paper, but I have been unable to ascertain to which of the Trigonia 

 he referred. 



No importance can be attached to the comparison of such types as 



* d'Orbigny (4), p. 84 ; Woods (3), vol. L, p. 27, pi. v., figs. 1-3 (1899). 

 t d'Orbigny (3), p. 754, pi. 489, figs. 1-3 (1848). 

 t Stow (1), pp. 497-514. 



