§ 44. ZOOPHYTES OF THE CARBONIFEROUS SYSTEM. T33 



exigences of the case? We might even carry the speculation 

 further, and suppose these countries to have been depressed to 

 so great a depth as to have been influenced by the radiation 

 of heat from the interior of the earth; and thus there may 

 have existed in temperate regions a local hot climate capa- 

 ble of supporting a tropical flora ? * The interest and 

 importance of a satisfactory solution of this problem have 

 led me to extend these remarks to a considerable length ; 

 and I offer them as mere suggestions, and with great 

 deference, f 



44. Zoophytes and Echtnoberms of the Carboni- 

 ferous System. — We must now briefly notice the animal 



* The most remarkable known instance of an area of land depressed 

 far below the sea-level, is that mentioned by Baron Humboldt. " In 

 descending eastward from Jerusalem to the Dead Sea, and the Valley 

 of Jordan, a view is enjoyed which, according to our present hypso- 

 metric knowledge of the earth's surface, has no parallel in any other 

 region. The rocks on which the traveller treads, with the open sky 

 over his head, are 13S8 feet below the level of the Mediterranean." — 

 Cosmos, p. 399. Col. Sabine's Translation. 



f Though from the revolutions which have swept over the earth's 

 surface, and the displacements and mutations which its crust has 

 undergone since the carboniferous epoch, there is but little probability 

 that any of the coal-fields are now in the same position in relation to 

 the sea-level, as at the period of their formation, I would, neverthe- 

 less, direct attention to the following statements and remarks of the 

 illustrious philosopher just cited. — " The depth of the Coal-basin at 

 Liege, is estimated by Herr Yon Dechen, at 3,809 feet below the 

 surface, and 3,464 feet beneath the level of the sea ; and that of Mons, 

 at 5,329 : while the lowermost coal strata of the Saar-Eevier are 

 computed by the same eminent observer to descend to a depth of 

 21,3 5S feet below the sea level, or 3.6 geographical miles. This is a depth 

 below the sea, equal to that of Chimborazo above it : and the tem- 

 perature would be 467° of Fahrenheit, if the increase be in the 

 supposed ratio of 1° for every 54 feet of vertical depth [ante, p. 34"), 

 We have, therefore, from the highest summits of the Himalayahs, to 

 the lowest portions of the basins which contain the fossil flora of the 

 carboniferous epoch, a vertical distance of about 48,000 feet, or — .th 

 of the earth's semi-diameter." — Cosmos, pp. 399, 400. 



