230 
M. L. FERNALD 
the New England-Gulf of St. Lawrence district. But these striking 
relationships are not confined to the northern hemisphere. South 
America, Polynesia, Australia and even Africa all show conspicuous 
cases of identity or generic affinity. One of the widely dispersed genera 
of the southern hemisphere is Schizaea, a group of fern-like plants with 
26 species, 25 of which are almost confined to the southern hemi- 
sphere (Australia, New Zealand, Polynesia, South America and South 
Africa), a few of them crossing the equator in the Tropics. No species 
is known in the Old World north of Madagascar, the Seychelles, India 
and the Philippines; i. e., the group is absent from practically the 
whole continental area of Eurasia and Africa. Similarly in the western 
hemisphere it is wanting in North America north of tropical Mexico and 
Cuba, with the single exception of one of the most famous species of 
the northeastern coastal area. This species, S. ptisilla, was described 
by Pursh from the Pine Barrens of New Jersey and almost simulta- 
neously by LaPylaie from Newfoundland, LaPylaie making the dis- 
cerning observation that the same species had been collected by 
Gaudichaud on the Falkland Islands. For three fifths of a century 
the Newfoundland record was held in suspicion, and it was believed 
that LaPylaie's specimens had really come from New Jersey. In 
1879, however, the plant was found in Nova Scotia by Mrs. Britton, 
and later rediscovered in Newfoundland by Waghorne, and inter- 
mediate stations on Cape Breton have been brought to light by Nichols; 
and I can state from personal observation that the great development 
of this unique plant is in Newfoundland where, with a species of the 
coastal plain genus Bartonia, it often fills the exsiccated depressions 
in the tundra. The species is, then, an extreme northern relic of an 
ancient group now generally confined to the southern hemisphere. 
I have mentioned LaPylaie's conviction that an identical plant occurs 
on the Falkland Islands. This is S. australis, which certainly is so 
close to the northern S. pusilla that little violence would be done 
exact classification if they were treated as one. 
Of very similar world-distribution is the family Xyridaceae but 
absent from Polynesia and more generally dispersed in Africa. North 
of Cuba and tropical Mexico the family is found only on the Atlantic 
slope from Texas to Newfoundland, with a couple of species in peaty 
habitats about the Great Lakes. The Haemadoraceae (fig. 18), 
likewise, belong primarily in the southern hemisphere, with 17 species 
in Australia, 11 at the Cape of Good Hope, and the remaining remnant 
