BRACHIOPODA—THOMSON. 37 
PART IL. 
GEOGRAPHICAL DISTRIBUTION OF THE BRACHIOPODS IN THE SOUTHERN SEAS. 
PREVIOUS DISCUSSIONS. 
The geographical distribution of recent Brachiopods throughout the whole world 
has been stated and briefly discussed by Suess, Davidson, Oehlert, and Hall and Clarke, 
but at the time these discussions were attempted (1852 to 1892) many cases of 
discontinuous distribution, which have since proved to be cases of erroneous 
determinations, were believed to exist, and the conclusions reached were thus 
lessened in value. Many of the errors in previous determinations were corrected 
by Blochmann (1908), who at the same time gave a most useful statement of the 
significance of the general facts of distribution. 
In 1892 Fischer and Oehlert gave an excellent summary of the then known 
distribution of the Brachiopoda of the southern seas, pointing out the unity of the 
faunas of the Arctic and neighbouring coasts as opposed to the diversity of the 
southern faunas. They grouped the latter into the following zoological provinces :— 
Magellan or Antarctic, New Zealand, Tasmania and Southern Australia, Cape of Good 
Hope, and the Kerguelen Islands. The similarities existing between the Magellan, 
Kerguelen, and New Zealand faunas on the one hand, and the differences from these 
displayed by the Australian and South African faunas on the other were sought to be 
explained solely by considerations of latitude and temperature. 
Dall (1894) in describing Macandrevia americana pointed out the possibility of 
a migration of Brachiopods and other marine organisms along the western coast of 
America. “It may be observed that there is nothing to prevent the free migration 
of northern forms into the South Pacific along the coast of the Americas. The writer 
has already the evidence to show that several species in deep water do extend from 
Behring Sea south to the vicinity of the Galapagos Islands, and, in the case of one 
species, Solemya johnsoni Dall, more than a thousand miles further south. With the 
known great range of many Brachiopods, there would be no apparent reason why 
species of the Panamic region, for instance, belonging to the northern type of 
development, should not extend their range southward, if opportunity arose.” 
As Jackson (1912) has remarked, the prescience of this eminent American 
author has been amply justified by the subsequent discovery of a Panamic species of 
Brachiopod, Macandrevia diamantina Dall, off Coats’ Land, Antarctic. 
Von Ihering in 1908 discussed the history of the fauna of the Magellan region, 
and gave lists of the species from Chil, Brazil, and New Zealand. He pointed out 
that the Tertiary Brachiopod fauna of Patagonia agreed more closely with that of 
New Zealand than with that of Chili, and argued that the Patagonian and New 
Zealand regions were each united to an Antarctic continent at that time, but that 
