356 Proceedings of the British Association. 
late Mr. Phillips, in drawing up a geological map of Cornwall, so 
far back as 1800. He suggested the propriety of tracing the lines 
of fissures into the coal districts, and also wished the directions of 
the lead lodes of the mountain limestone to be ascertained, as likely 
to lead to general results. 
Section D.—Zoo.tocy anp Borany. 
Dr. Richardson resumed the reading of his Report on the Zoology 
of North America. In touching upon the geographical distribution 
of the Mammalia, he remarked the great similarity which existed 
between them and the European species ; whilst there was the great- 
est dissimilarity to those of South America. The boundary line 
separating the Faunas of North and South America, was not at the 
Isthmus of Darien, but at the tropic of Cancer. No Quadrumana 
occur to the north of the Isthmus of Darien; though in Kurope 
there is a species which ranges as far north as the rock of Gibraltar, 
in latitude 36°.—In the order Carnivora, and family Cheiroptera, 
all the North American species belong to that tribe which possesses 
only one bony phalanx in the index, and two in each of the other 
fingers, to which tribe also all the European bats belong, except an 
Italian species of Dinops. None of the sixteen species recorded 
as natives of North America have been found elsewhere ; two only 
have been traced over any great extent of country, and one of these 
(resembling the European Pipistrellus) ranges through 24° of lati- 
tude, and is the most northerly species in America. There must be 
still many bats to be discovered in that country, as those of Mexico, 
California, and the whole track of the Rocky Mountains are entirely 
unknown. Of the family Insectivora, ten species were enumerated ; 
and it was stated that North America differs more from Europe in 
this family, than in any other of the order Carnivora. Three of the 
European genera do not exist in North America, and the three ge- 
nera found in North America do not exist in South America. The 
North American species of Sorex, however, closely resemble those 
of Europe.—Of the family Mihengiets, inhabiting the New World, 
only three species reach into North America, the rest being confined 
to the south of the Isthmus of Darien. Two of these occur n0 
higher than Mexico ; but the third (the Virginian opossum) ranges 
to the great Canadian lakes on the north, and to Paraguay on the 
south.—About forty species of the family Carnivora have been no- 
ticed; and this family includes a greater number than any other 
