180 POPULATIONS OF THE SEA 



marine and terrestrial biotas of the southern hemisphere were 

 enabled to encircle it, but were retarded as to movement in a 

 northward direction, or receipt of northern admixtures, by some- 

 thing geologists like to call Gondwana [Land of the Gonds (Caster, 

 1952, p. 126)]. Gondwana, or Gondwanaland, has commonly been 

 interpreted as a more or less east-west, transoceanic land mass 

 whose composition varies with author and time but which generally 

 includes a large part of Africa, usually parts or all of South America 

 and India, and commonly Australia and Antarctica (for recent 

 summaries see Teichert, 1958; King, 1958). 



Similarities in the Early Devonian marine faunas of South 

 America and South Africa have long attracted attention, and 

 recently have been extended to include Tasmania (Boucot and 

 Gill, 1956). These similarities played a prominent part in a recent 

 symposium on the problem of land connections across the South 

 Atlantic (Mayr et al., 1952) and were one of the key factors leading 

 to the principal conclusion drawn by some participants of that 

 symposium that a "faunal connection" and presumably a land 

 connection "seems to have existed until at least 180 million years 

 ago, but was no longer in existence 130 million years ago" (Alayr, 

 1952, p. 257). Indeed, the evidence for continuity of Devonian 

 land between Africa and South America was so vigorously and 

 persuasively presented by Caster (1952) as to stimulate review 

 and search for an alternative. 



Figure 9 compares Early Devonian faunal relations from South 

 Africa to South i\merica, with different patterns of distribution 

 found among the living shelly benthos and an Oligocene Tethyan 

 example. These data, to be sure, are of very unequal value, and 

 some are badly in need of revision and refinement. They do, 

 however, gixe a rough order of relations which may be interpreted 

 as implying either (1) a similarity of biogeographic relations 

 between the southern hemisphere marine Devonian and the 

 Oligocene Tethyan and Recent Indopacific, or (2) a tendency 

 toward a higher proportion of nomenclatural identities between 

 contemporaneous smaller faunas of like ecology regardless ot 

 other factors. 



I am not merely quibbling, therefore, when I urge, as Dunbar 



