NEWTON : FOSSIL PEARL-GKOWTHS. 133 



been more or less customary for Continental palaeontologists to regard 

 this form as Mantell's Inoceramus Cripsi, whereas the English species 

 has much more median umbones, being consequently of different 

 contour, besides belonging to an older stage (Cenomanian) of the 

 Cretaceous series. D'Orbigny recognized a distinction, and gave the 

 name Goldfussianus to the shells figured and described by Goldfuss as 

 Inoceramus Cripsi of Mantell. At a later date the same author in his 

 " Prodrome " restricted the species Goldfussianus to the specimen 

 represented by fig. Ad of Goldfuss's pi. cxii — figs. Aa, h, and c of 

 that same plate being recognized as his /. regularis. Both these 

 species, Ooldfusxianus anA regularis, are of Upper Senonian (Campanian) 

 age, being known to occur, at the time of description, in Westphalia 

 (Haldem, Dnlraen, etc.) and certain areas of France (Royan, etc,). 



A preliminary note on the nomenclature of some of these Senonian 

 Inocerami has been recently published by Dr. Job. Bohm, who promises 

 a more extended account on completion of his researches ("IJher 

 Inoceramtis Cripsi, Mant." : Monatsber. Deutsch. Geol. Ges., 1907, 

 No. 4, p. 113). 



The specimen now referred to, as delineated in the original figure, 

 measures 125 mm. in length and 65 mm. in height. 



Geological age. — Cretaceous (Campanian). 



Locality. — Haldem, Westphalia, Germany. 



Inoceramus exbansus, W. H. Baily. PI. IV, Figs. 2, 3. 

 Inoceramus expansus, W. H. Baily : Quart. Journ. Geol. Soc, 1855, 

 vol. xi, p. 462, pi. xiii, fig. 5 ; H. Woods, Annals South African 

 Museum, 1906, vol. iv, p. 299. 



This species of Inoceramus is one of the most characteristic Pelecy- 

 pods of the Upper Cretaceous rocks of Pondoland in South Africa. 

 It frequently occurs with the original shell - structure preserved, 

 although just as often it is represented by convex natural casts of the 

 interior. Some of these casts exhibit the equidistant concentric 

 ridges, separated by wide sulcations, and an entirely smooth surface ; 

 others, as in the specimens figured (a left valve), bear numerous small 

 rounded cavities of nearly equal size, arranged concentrically with 

 the sculpture-markings, and agreeing in all respects with what has 

 been observed in Inoceramus Goldfussianus. These pittings are present 

 on both valves, as shown by the specimen representing a fragmentary 

 cast, with parts of both valves exhibiting the postero-umbonal view. 

 These specimens are also furnished with some feeble radial striations, 

 emanating from the umbonal region, and extending to the ventral 

 margin, being more obvious on the lateral areas than elsewhere. 



A wax impression of the single valve yields a beautiful result, the 

 rounded and elevated prominences showing out quite clearly, as well 

 as the faint radial striations. No mention is made in Baily's original 

 description of the pittings now called attention to, nor has Mr. H. Woods 

 noticed this phenomenon in his more recent account of the shell. The 

 single valve has a length of 95 mm. and a height of 105 mm., whilst 

 the specimen with both valves in the closed condition shows a diameter 

 of 60 mm. and a height of 130 mm. 



