TJie Invertebrate Fauna of the Uitenhage Series. 187 



the final phase of individual growth, and it is only in this whorl 

 that the umbilical wall has been satisfactorily exposed and freed 

 from the matrix. 



The predominance of Holcostephani in the cephalopod-fauna of 

 the Uitenhage beds is no less striking than the manner in which 

 certain of these lend themselves to close comparison with European 

 forms. There is apparently near relationship to types well distributed 

 in the Valanginian and Hauterivian of the European continent and 

 more sparingly represented in England, and in this fact we may 

 recognise the most reliable evidence for a correlation of the 

 Uitenhage Marine Beds with European standards. It will be 

 well, for the present, to regard with the greatest caution the ap- 

 parently peculiar geographical distribution of Holcostephamts, since 

 so little is yet known of any cephalopod-faunas, in tropical or sub- 

 tropical latitudes, which may be brought into correlation with that 

 of the Uitenhage Series. Some remarks on this subject have already 

 been made in the previous section of this memoir. 



I have to acknowledge my indebtedness to Mr. G. C. Crick for 

 kindly assisting me to compare some of the specimens described 

 below with representatives of Holcostephanus preserved in the British 

 Museum (Natural History). 



HOLCOSTEPHANUS ATHERSTONI (Sharpe). 



1856. Ammonites atherstoni D. Sharpe, Trans. Geol. Soc. Lond., 



ser. 2, vol. vii., p. 196, pi. xxiii., fig. 1. 

 1882. Olcostephanus atherstoni M. Neurnayr, in E. Holub and 



M. Neumayr, Denkschr. d. k. Akad. Wiss., Math. -Nat. 



01., Band xliv., p. 272. 

 1892. Olcostephanus (Astierm) atherstoni A. P. Pavlow (partim], in 



A. P. Pavlow and G. W. Lamplugh, Bull. Soc. Imp. Nat. 



Mosc., annee 1891, Nouv. Ser., tome v., p. 495 (p. 137 of 



authors' copy). (Probably not pi. xvii., fig. 14.) 

 Occurrence. Collected by Miss M. Wilman at Coega. A specimen 

 from the South African Museum is probably from the Sunday's 

 Eiver. The type-specimen in the Geological Society's collection in 

 London is from the Sunday's River (registered 10975). Messrs. 

 Eogers and Schwarz have recorded this form from the Zwartkop's 

 Eiver valley in the neighbourhood of Uitenhage. :;: Mr. Eogers has 

 also noted its occurrence at several localities in the valleys of the 

 Coega and Sunday's Eivers. | 



* Rogers and Schwarz (1), p. 9. t Rogers (2). 



