Obs. In the preceding table, and in that which follows, species that range to several zones are enumerated in each. The proportionate numbers of the second table are found by dividing the whole Phanerogame of a district by the numbers of each family in that district, and they may, therefore, be considered as denominators of fractions having 1 for a numerator.

The proportions vary remarkably in different districts. The predominance of Compound Flowers, Leguminous and Rosaceous plants in the Prairies, combined with the paucity of Saxifrages, Gentians, and Ericaceous plants, affect the proportions of the other families materially. The Grasses, as might be expected, are more numerous in the Prairies than elsewhere, with the remarkable exception of the Polar Zone, in which the Graminee form one-seventh of the species, and in conjunction with the Crucifera, Caryophyllea, and Saxifrage, constitute more than half the Phanerogama. The small numbers of Asters, Willows, and Carices on the Pacific coast, modify the numbers of that district.

FAMILIES.

PROPORTIONATE NUMBERS OF SOME OF THE PRINCIPAL FAMILIES TO THE WHOLE PHANEROGAMOUS VEGETATION OF THE SEVERAL DISTRICTS OF THE THREE ZONES.

A list of the plants collected by Mr. Seeman on the coasts of Beering's Sea having been received subsequent to the first part of the preceding tables having passed through the press, some emendations are requisite. The numbers of Dycotyledones, in p. 461, are to be substituted for those in p. 445, and the following changes made in the column headed Kotzebue Sound: viz. Ranunculacea, 14; Crucifera, 19; Caryophyllea, 18; Leguminosa, 14; Rosacea, 27: Portulacea, 5; Saxifragee, 26; Composita, 36; Ericee, 9; Boragineæ, 5; Scrophularinee, 12; Verbenacea, 1; Diaper siacea, 1. These occasion some slight alterations in the first column of the second zone, and in the total number of plants.

Arctic Region.

Polar Zone.

North of 73° Lat.

TABLE OF DISTRIBUTION OF CARICES.

463

The following Table of the Distribution of the Carices was drawn up by Dr. Boott, whose intimate acquaintance with that genus of Cyperacea renders it of the highest value to the student of the Geography of Plants.

MY DEAR SIR JOHN,

London, May 6, 1850.

I have examined the Carices you brought from your last excursion to America. They are

. scirpoidea Michx. Arctic Sea coast.

ursina Dewey. Arctic Sea coast.

glareosa Wahlg.

Arctic Sea coast.

compacta Brown. Arctic Sea coast.

fuliginosa St. & Hoppe. Arctic Sea coast.

livida Willd. Arctic Sea coast.

Nova Angliæ Schwz. Arctic Sea coast and Methy Portage. canescens L. (& b.) Arctic Sea Coast and Methy Portage.

66 var. polystachya. Lakes Superior, Rainy and of the Woods.

adjusta Boott. Methy Portage.

siccata Dewey. Methy Portage, Saskatchewan.

lanuginosa Michx. Methy Portage, Saskatchewan.

lenticularis Michx. Methy Portage.

Houghtonii Torrey.

Methy Portage.

Raeana Boott. Methy Portage.

utriculata Boott. Methy Portage, Lakes Superior, Huron.

aquatilis Wahlg.

Methy Portage, Lakes Superior, Huron, Fort Simp

scoparia Schk. (& b.) Lakes Superior and Huron, Winipeg, Athabasca. vulgaris Fries. Lakes Superior and Huron, Winipeg.

retrorsa Schwz. Winipeg River, Lake of Woods.

pedunculata Muhlg. Winipeg River, Rainy Lake.

intumescens Rudge.

Lake of Woods, Rainy Lake.

Ederi Ehrh. Rainy River and Lake.

Pennsylvanica Lam. Saskatchewan, Winipeg, and Cumberland Lakes.

incurva Light. Valleys of the Sask. and Mack.

Of the above, C. Raeana is new, and C. stans new to British America. I find from my notes that the number of Carices in North America is 250; of which 178 are found in all Arctic America, including 97 common to Arctic America and the States, leaving 81 Arctic species.

Of these 81, there are 36 common to Europe, leaving 45 peculiar to Arctic America.

Of the 97 found in Arctic America and the States, 28 are common to Europe, leaving 69 exclusively American.

There are in the States, besides, 72, of which 4 only are European, leaving 68 exclusively American.