49S 
ZOOLOGY OF NORTH AMERICA. 
cessary writing-. Maps of this kind had 
been given to the Geological Society by 
the Archduke John of Austria. 
Section P.-ZOOl OGY ANO BOTANY. 
President— Professor Henslow 
P'ice PresidenU —^ i^v F. W. Hope, Dr. I, 
Richardson, Professor Royle. 
Secretaries John Curtis, Esei , Professor Do 
Dr Riley, S Rootsev, Esq 
Committee— W/ l Unm Yarrell, Esq , Rev Mr 
Jenyiis T. Mackay, Esq, C B ibiuotoH, 
Esq., Professor Nilsson, Hon. Charles Har- 
ris. Rev Mr Phelps Richard Tay or. E>q , 
T C Fly ton, Ksq , E Uowinan, Esq W 
C, Hewitson . Professor Scouler, Dr. aci)b, 
Rev Mr. Ellei I'lnbe, G . . .lelfrys. Esq , R 
M Bail Esq , Colonel Sykes, .1 L. Knapp, 
Esq..-Vi{^ors, Esq , E Forster, Esq 
Dr. Richardson commenced the pro- 
ceedings of the Section, by reading the 
introductory portion of his report ‘ On 
the Zoology of North America.’ It did 
not appear probable that the progress 
of colonization had, as et, extinguish- 
ed any one species of animal from the 
country. The great similarity existed 
between the animals of North America 
and those of Europe, as regarded their 
generic distinctions, connected with the 
dissimilarity of their species, rendered 
them well adapted to inquiries connect- 
ed with their respective geographic dis- 
tribution. Hitherto, the trivial names 
bestowed by the colonists upon many of 
those of North America, had tended to 
mislead naturalists. The observations, 
in the present report, would principally 
refer to the western parts of North A- 
merica, including New Mexico, the 
Peninsula of Florida and California, 
down to the well-defined limits of the 
very different South American zoologi- 
cal province. Dr. Richardson then 
proceeded to describe the physical struc- 
ture of thi' country, of which the Roc- 
ky Mountains formed a most remarka- 
ble feature. The altitude of many of 
their peaks rose above the limits of per- 
petual snow, and their sides were flank- 
ed by zones of different temperature, 
affording passages for animals from the 
Arctic circle to the Table Lands of 
Mexico, without any great alteration of 
climate throughout the whole extent. 
The temperate zones of both hemispheres 
might, in this way, be connected, 
were it not that the Cordilleras were 
greatly depressed at the Isthmus of 
Panama, and that a plain extended 
from sea to sea, a little further to the 
south. As yet, we possess no informa- 
tion of the elevation of the backs of 
these mountains, independent of the 
heights of some of the peaks, and the 
elevation of the base of the range is 
equally unknown. The depths of some 
of the transverse valleys are considerable, 
and these afford passages for the mi- j 
gration of animals. Most oftheprin- j 
cipal rivers flowing to the east cut | 
across the chain, and one actually rises 
to the west of the crests of the range. ! 
On the Atlantic side, are prairies, com- 
[losing plains, gently inclining to the ' 
east, and there is an extent of land 
wdiichmaybe likened to a long valley, 
which stretches from the Arctic sea to 
Mexico, witlu'ut any transverse ridges 
dividing it, but merely affording three ; 
distinct water-sheds. The greatest width 
of the jdain is about 15" of longitude, 
in the 40® to 50® of north latitude. 
This configuration gives great facility 
for the range of herbivorous quadrupeds 
from north to south, and for the migra- 
tion of low flying birds, whilst the Mac- l' 
kenzie furnishes a channel by which i 
the anadromons fish of the Arctic Sea i 
can [lenetrate 10'^ or 11® of latitude to j 
the southward, and the Mississippi 
enables those of the Gulph of Mexico 1 
to ascend far to the north. The most i 
remarkable chain east of the Mississippi, | 
is the Alleghanies, which are about 100 i 
miles broad, rise from a base between , 
1,g 00 and 1,200 feet, and attain an eleva- ■ 
tion from 2,000 to 3,000 feet above the 
sea. The strip of land between them | 
and the Coast is two hundred miles I 
broad in Southerly to the 5® of latitude 
these forming also the Carolinas ; be- j' 
comes broader still in Georgia, and ' 
sweeping round the northern extremity i 
of the chain, joins the valley of the Mis- i 
sissippi. This strip influences the dis- ■ 
tribiition of animal life, by extending a 
barrier to the progress of anadromous 
fish from the Atlantic to the bottom of 
the Gulph of Mexico. With reference to ; 
Physical Geography, Newfoundland ap- 1 
pears as a prolongation of the Atlantic i 
coast line, and its zoological and botani- 
cal productions correspond to those of j 
Labrador, 
When the canals already projected 
shall have opened a communication be- 
tween the several great inland seas which ;i 
exist in North America, an interchange 
will take place between the fish of wide- 
ly diverging waters. 
