FAUNISTIC PROBLEMS 
381 
It is now fifty years since Mr. Andrew Murray * first 
directed attention to the fact that the beetle fauna of Old 
Calabar in West Africa presented certain affinities with that 
of South America. He even then suggested that some sort of 
communication must once have existed between these two 
regions of the earth. A few years later he returned to the 
same problem, expressing the opinion that this communica¬ 
tion consisted of an actual land bridge of which the only re¬ 
maining vestiges are the islands of Ascension, St. Paul’s, St. 
Helena and Tristan da Cunha.f 
Great stress is also laid on this remarkable relationship 
between the southern continents by Professor Kolbe,J hut he 
explains it by the assumption of a land bridge far to the 
south of the Equator. 
Dr. Packard § was good enough to inform me some years 
ago that the distribution of the Lepidoptera was distinctly 
in favour of the theory of a former union between South 
America and Africa. He alluded in particular to a family of 
moths known as the Satumidae, stating that their general 
range confirmed the view arrived at from other sources, that 
perhaps at the close of the Cretaceous Period and through 
the early part of the Tertiary Era the two continents were 
connected with one another by land. 
The importance of the fresh-water crabs in the solution of 
problems of this nature has been emphasised, as I mentioned 
before, by Dr. Ortmann,|| who showed that the west African 
Potamoninae are geographically most closely approached by 
the South American Potamocarcininae, and that, this suggested 
a former union of these regions. This land bridge in its full 
extent, he thinks, existed during the Jurassic and in early 
Cretaceous time. In the middle of the Cretaceous Period the 
southern Atlantic advanced northward and gradually invaded 
the east coast of South America extending as far as the 
Amazon valley. Guiana still remained joined to West Africa 
during the remainder of the Cretaceous Period, and was not 
* Murray, A., “ Coleoptera of Old Calabar,” pp. 453—454. 
t Murray, A., “ Coleopterous Faunae,” p. 15. 
t Kolbe, H. J., “ Die Copropbagen Lamellicornier,” p. 503. 
§ Packard, A. S., “ Larval Forms of Moths,” p. 280. 
|| Ortmann, A. E., “Distribution of Decapods,” pp. 350 — 351. 
