The Invertebrate Fauna of tlie Uitenhage Series. 127 



Cretaceous, at Caryilauhue (Argentine) ; this is accompanied by 

 a typical member of the Cretaceous section Scabrse, T. transatlantica 

 Behr. T. anguste-costata is a small triangular shell, which in the 

 delicate character and close spacing of the flank-ribs recalls the 

 Indian T. parva Kitchin, from which, however, it is widely 

 distinguished by the very different outline and the delicate ornamen- 

 tation of the area. In the perfect development of these longitudinal 

 ridges of the area, T. anguste-costata retains in typical manner an 

 essential feature of the section, a differentiation of the valve- 

 sculpture which so strongly and constantly characterises all the 

 Costatse. With reference to the occurrence of the costate Trigonia 

 in Cretaceous rocks, Behrendsen cites, in addition to T. peninsu- 

 laris Coquand and T. carinata Agass., the following shells : T. longa 

 Ag., T. pennata Sow., T. cardissa Ag., and T. indica Stoliczka. This 

 list, however, is misleading, as may be ascertained from a careful 

 examination of these forms. T. longa and T. pennata certainly 

 cannot be included in the section Costatae, while it is doubtful 

 whether T. indica stands in very close connection with this division. 

 T. cardissa, on the other hand, is a typical representative of the 

 section, but it has been shown to be Jurassic," and not Cretaceous, 

 as at first suggested on insufficient grounds by Agassiz. 



GENUS CAEDITA J. G. Bruguiere. 



CARDITA NUCULOIDES Tate. 

 Plate VII., figs. 5, 5a, 5b. 



1867. Cardita nuculoides E. Tate, Quart. Journ. Geol. Soc., vol. 

 xxiii., p. 162, pi. vii., figs. la-Id. 



Occurrence. Tate's figured specimen, numbered 11028 in the 

 collection of the Geological Society, came from the Sunday's Eiver. 

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

 Coega Valley, half a mile down from the railway (466g). 



Remarks. The specimen found by Mr. Eogers is a well-preserved 

 left valve which differs slightly in outline from Tate's figured type : 

 it is a little more drawn out obliquely, and the convex fold of the 

 valve which runs obliquely from the umbonal region to the postero- 

 ventral corner is rather more pronounced than in the original 

 type. Tate's specimen, however, although having both valves in 

 place, is not so perfectly preserved, and some allowance may also 

 be made for individual variation. The general form of the shell, 



* Bigot (1), p. 292. 



