RECENT BRACHIOPODA 273 



sphere, and its other main distribution is along the north shore of Gond- 

 wana (2 species in the western Mediterranean), extending as far as the 

 Antilles (1) on the west (none are present off western South America), 

 on the east into the Indian Ocean (1), and probably across Asia in 

 former Tethys to the Pacific. Along the southern side of Gondwana the 

 genus probably spread along the shores of the Indian Ocean to south- 

 eastern Australia (1) and to the Cape of Good Hope (2). In the vast 

 area of the Atlantic Ocean between Africa and South America there is 

 but a single species, and this is the Antillean T. cailleti, occurring off 

 Brazil at Pernambuco and Kio de Janeiro and as a relict in the mid- 

 oceanic island Ascension. 



DyscoUa wyvillii probably originated in ancient Tethys, where its an- 

 cestor, D. guiscardiana, is found in the Pliocene of Sicily. The living 

 species is rare at the Maldives in the Indian Ocean, but is more common 

 in the Atlantic off Spain, Portugal, northwestern Africa, and the Cape 

 Verde Islands. As a relict it occurs off the Lesser Antilles. The other 

 form, D. crossii, originally described from the east shore of Japan, is 

 also reported by Fischer and QEhlert from Punta Arenas, in the Magellan 

 Straits, and from New Year Sound. By combining the distribution of 

 these two species we see that the genus has extended itself along the 

 northern, western, and northeastern shores of Gondwana, and from the 

 Austral waters to Japan, probably by way of Oceanica. While the genus 

 is known only since the Pliocene, its large size and primitive loop makes 

 it probable that its origin goes back to the Cretaceous. Its nearest rela- 

 tive is Terebratulina, which had its origin in the Jurassic. 



Liothyrina. — This genus has the greatest number of species of all liv- 

 ing genera (14), even more than Terebratulina. Its geographical distri- 

 bution has recently been worked out by Blochmann (1908, plate 40) with 

 the greatest care. The center of distribution was the north shore of 

 Gondwana (Atlantic-Poseidon), where (western Mediterranean) at least 

 5 species are living. From the Antillean region (2) the genus extends 

 down the west side of South America (3 species, 1 L. uva), and thence 

 eastward into the Antarctic region to the Falklands, South Georgia, south 

 of Africa, Kerguelens, Saint Paul (south Indian Ocean), and Kaiser 

 Wilhelm Land to southeastern Australia. From the Australian region it 

 probably spread northwest through Oceanica to Japan, where 2 species 

 occur, but no linking forms are known to live now in the intermediate 

 region. From the Mediterranean region the genus spread less abun- 

 dantly northward along western Europe (2) into the Arctic region (1) 

 of Jan Mayen, Iceland, and the east coast of Greenland. None are on 

 either side of the North American continent. From the Magellan region 



