TJie Invertebrate Fauna of the Uitenhage Series. 229 



Lower Cretaceous series in Europe. A surer guide may be 

 recognised in some of the Cephalopoda, more especially in the 

 representatives of Holcosteplianus (sensu stricto) which so pre- 

 ponderate in the Uitenhage cephalopod-fauna. It is obvious that 

 these have very near allies in Europe which are confined to the 

 Upper Valanginian and Lower Hauterivian, and this fact may suffice 

 to justify the provisional approximate correlation of the Marine Beds 

 with this part of the Neocomian. 



In the attempt to trace relationships between the Uitenhage 

 molluscs and those of Lower Cretaceous deposits in extra-European 

 regions, the desirable evidence to be derived from a comparison of 

 cephalopod-types is as yet not forthcoming, if we except the single 

 case of Holcosteplianus schenki (Oppel), from the Spiti Shales, which 

 is closely allied to some of the South African Holcostcphani. Certain 

 well-characterised lamellibranchs, on the other hand, some of which 

 are of a very specialised nature, point to the bonds by which this 

 development of the Neocomian in Cape Colony is connected with 

 the Oomia Trigonia-heds of Cutch, the strata yielding Trigonia 

 ventricosa in the Godavari district and in Hazara (Himalayas), the 

 Neocomian deposits of German East Africa, and the Lower Cretaceous 

 strata of presumably like age in Chili, Bolivia, and the Argentine 

 Eepublic. In comparing the faunas, importance must be attached 

 to the evidence of some of the Trigonia, notably of the divisions 

 Scabrae and Pseudo-quadratse. In particular, the points of contact 

 revealed by a comparison of the lamellibranch-fauna of the Uitenhage 

 Series with that of the Oomia Trigonia-beds are found to be very 

 remarkable, and of such a kind that we must infer the approximate 

 contemporaneity of these two faunas, and the existence of facilities 

 for intercourse between the two areas. It becomes, therefore, a 

 matter for some surprise that the Uitenhage ammonitoids or forms 

 closely allied to them are as yet unknown in Cutch, and the real 

 or apparent absence of such forms from the Neocomian deposits of 

 German East Africa and of South America is also a striking circum- 

 stance. 



The Relation of the Fauna to some Questions of Distribution. 

 A careful comparative study of the Uitenhage Mollusca dispels the 

 idea, emphasised by Neumayr, that this fauna proclaims its isolated 

 position by the sharp contrast it affords to the comparable faunas of 

 other regions, and that it may therefore be considered to support the 

 theory of an Indo-African land barrier in early Cretaceous times. 

 Neumayr laid principal stress upon the contrast between the fauna 

 of the Neocomian Belemnite-beds in the north-west of Madagascar 



16 



