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. — Zoology and Botany. 



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 Europe 

 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 

 fino^ers, 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 Marsupiata, 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 no 

 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 



