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Show 1905.] AMPHIBIANS AND REPTILES. 229 recorded from the hot-lands 70 or 69 per cent.! I have left the two lists as they are, for fear that a revision would not be free from bias and might thus prove too much *. Fairly established is the fact that the Tierra Fria is inhabited by about 34 per cent., one third of the total number of species, of which one half, i.e. 17 per cent., are restricted to the cool and cold zone. Equally safe is the conclusion that in the Tierra Caliente occur 69 or 70 per cent., about 50 of which (51 or 43) are restricted to it. This shows the richness of tropical life, especially if we consider the small extent of the hot-lands in Mexico in comparison with the rest of the country. Text-fig. 30. i4ooo rrm* 12000 .... -lo on flff f:':'|fg[gjlUll TIERRA TEMplada k i v ^ v it J i B H H tierra ca l ien t e . SEA LEVELt ■> vi\.\sV"v o ■:..........................H a l ------------------------------ ------------------------ -- Diagram of the distribution of 250 Mexican species according to Altitude. Per cent. Restricted to the Tierra Caliente .............. 41 Ascending into temperate zone .................. 16 Ascending into cool zone.............................. 5 Species restricted to the temperate zone ... 6 Restricted to cool and cold zone.................. 17 Descending into temperate zone.................. 8 Descending into hot zone ......................... 4 100 Further, the whole fauna is practically composed of these two groups, whilst the species restricted to the temperate zone form a very small minority, 6 per cent., at the utmost 10 per cent, if we allow for the difficulty of classifying. This shows that the original stocks were either cool or tropical, * Probably all the numbers of species, as put down for the six groups, have been understated, but this would not much alter the proportions. I- or instance, on p. 228, the species given as occurring in cool to hot zones amount to about 24, but even half a dozen more might be added according to the interpretation of such records as " Amula" and C( Omilteme,' which may mean an3rthing from 5000 to 8000 feet. Southern or hot-country species. Northern or | cool-country species. J I v'.V'N ' w \ \ J T □ |