' ' RECENT BRACHIOPODA 271 



sina (off South Africa and Tasmania), Bonchardia (off Rio de Janeiro 

 and abundantly fossil in Antarctica), Magellania and Terebratella 

 (Chile, Magellan Straits, Patagonia, Australia, New Zealand, Tasmania, 

 Kerguelens, and Antarctica). Megerlina seems to be restricted to the 

 Australian region. There are other genera in these waters, and these 

 are regarded as migrants to be discussed under Gondwana. This region 

 is faunally directly connected with Oceanica. 



OGEANIGA 



This region is not rich in brachiopods and has 3 restricted but widely 

 distributed genera. From the Austral region there have migrated into 

 the Australia-lSTew Zealand area Kraussina, Magellania, and Terebratella, 

 but they are not known north of these land masses. Common through- 

 out this island realm are the restricted genera Lingula (also sparingly 

 present in the Indian Ocean), Frenulina, and Basiliola (restricted to 

 Hawaii) ; the two first named genera extend their range to Japan. 



GONDWANA 



The remaining brachiopod genera, 14 in number, appear to owe their 

 dispersion in the main to the former but now much broken shore of 

 ancient Gondwana. The present Mediterranean is the remainder of the 

 ancient and far more extensive Tethys, always more or less in connection 

 with the North Atlantic (= Poseidon) and in early Tertiary time com- 

 municating freely with the Indian Ocean. Tethys is tbe boundary of the 

 northeastern area of Gondwana, and the shore thence continued west- 

 ward across the Atlantic from northwestern Africa, possibly by way of the 

 Canary and Cape Verde Islands, to Venezuela and the Antillean region. 

 Western Gondwana, however, was being severed by Poseidon and Nereis 

 (North and South Atlantic) during the Cretaceous, and their union 

 into the present Atlantic certainly took place during the early Eocene. 

 During the Tertiary previous to the Upper Miocene there was also an 

 open seaway between the Caribbean-Panama region, so that the northern 

 Gondwana faunas could readily continue their march south along the 

 western side of South America into the Antarctic realm, whose waters 

 were then much warmer than they are now. Of these Gondwana brach- 

 iopods but few, however, got into the North Pacific. To make this im- 

 mensely long and very important migration route clearer, it will be 

 necessary to present the geographical range of the genera of this realm 

 in detail. 



Restricted to the Mediterranean-Cape Verde and Portugal-England 

 regions there are the 3 genera Gwynia, Megathyris, and Miihlfeldtia 



