the Uitenhage Series—Cape Colony. 293 
A search for traces of the characterising features of the Uitenhage 
fauna among the Lower Cretaceous fossils described from South 
America also reveals evidences of a suggestive kind, as recognised 
by several authors. From the Belgrano Beds in Patagonia, T. W. 
Stanton! has described two Zrigonie which at once recall South 
African forms. TZ. subventricosa, Stanton, appears to be nearly allied 
to Z. ventricosa (Krauss), and 7. heterosculpta, Stanton, not only 
exhibits a peculiar type of adult ornamentation comparable with that 
exemplified by Z. vau, Sharpe, and another related South African 
form, but its adolescent characters show that there is in all probability 
true relationship with this group of Z. vaw. Here, again, in the 
Belgrano Beds is found an associated Gervillia of large dimensions 
which does not seem to be widely removed from G'. dentata, Krauss, of 
Cape Colony. From Chili, R. A. Philippi has described Zrigonia 
which share the characters of peculiar sculpture and siphonal pro- 
longation exhibited by the group of Z. vau, Sharpe, and are probably 
related forms. The Zrigonie of the group Pseudo-quadrate described 
by G. Stemmann, R. A. Philippi, and C. Burckhardt from Lower 
Cretaceous beds in Bolivia, Chili, and the Argentine Republic, form 
an important connecting link with the Uitenhage fauna. 7° transitoria, 
Steinmann, a member of this well-marked group, occurs with significant 
associates in the Zrigonia-beds of Neocomian age exposed on the left 
bank of the Rio Agrio opposite Las Lajas, Argentine Republic.* 
These beds yield another member of this group of Zrigonia, and also 
a species which very closely resembles 7. conocardiiformis (Krauss), 
one of the most characteristic forms in the Uitenhage fauna. 7. eximia, 
R. A. Philippi, from the Tinguirica valley in Chili, appears to be 
very closely related to these. The Chilian shells ascribed by Bayle 
and Coquand to Ostrea coulont bear a considerable resemblance to 
Exogyra imbricata, Krauss, of South Africa, with which Coquand 
himself later ventured to identify them. Accompanying this oyster 
in Chili is Z. delafossex, Bayle & Coquand, the resemblance of which 
to Z. ventricosa (Krauss) has been remarked upon by J. Lycett, 
W. Paulcke, and myself. 
From this brief sketch it may be seen that certain groups of bivalves 
which form characterising elements as yet unknown to occur in 
Europe, have a remarkably wide distribution in a Neocomian develop- 
ment of southern type. Thus, Zrigonie of the group Pseudo-quadratée 
occur in India, Cape Colony, and South America; TZrigonie of 
degenerate costate type, unknown elsewhere, are found in Cutch and in 
German East Africa; Zrzgonie of the groups of 7. v-scripta or T. vau 
occur in Cutch, German East Africa, Cape Colony, and South America ; 
Trigone of the type of 7. ventricosa are also met with in India, Kast 
Africa, Cape Colony, and South America; the remarkable form 
TL. conocardiiformis has a close counterpart in South America; the 
genus Seebachia is known from Cutch and Cape Colony, while a species 
of Cucullea which exhibits some striking distinguishing features has 
1 T. W. Stanton: Rep. Princeton Univ. Exped. to Patagonia, 1896-1899, vol. iv, 
pt. 1, Marine Cretaceous Invertebrates, pp. 18, 20, 1901. 
2 C. Burckhardt, ‘‘ Beitrige zur Kenntniss der Jura- und Kreideformation der 
Cordillere’’ : Palontographica, Band t (1903), pp. 72-75. 
