“ A few comparisons of the hepatic flora of the two continents will prove suggestive; we select only the larger genera.
Aside from the dozen or more ubiquitous species, all of which are common in Europe, the species of North American Hepaticæ may be arranged in four floral regions or provinces. These were first outlined in our first venture at the study of our species1 and further information has tended to strengthen the belief that they are fairly natural ones, with only such transitional forms as are common wherever lines are attempted on the face of Nature. ”

“ The committee who arranged this series of papers on the distribution of North American plants could not have been aware of the fragmentary knowledge we possess of the distribution of the Hepaticæ in North America, otherwise this paper of the series would certainly have been omitted. There is possibly no other major division of plants of which we know so little of the range of species in latitude, in longitude, or in altitude. A few small areas of our country have been more or less carefully studied. ”

“ How far this local collection is a necessity is thoroughly illustrated by the fact that every corner hitherto explored brings to light new and unexpected forms. A large number of species accredited to America are known only from the specimens which Austin collected in the vicinity of Closter, N. J., and careful searching in other regions will furnish others of equal interest. ”