336 On the Structure of the Delta of the Ganges. 



man, " is not thoroughly fossilised, for when heated by the 

 blow-pipe it becomes slightly charred, and emits a percepti- 

 ble odour, but the animal matter left is exceedingly small, 

 and the whole loss on heating a portion of it to a white heat 

 was only seven per cent, the greater part being moisture 

 from the hydrate of iron with which it is impregnated. The 

 greater part of the phosphate of lime remains, with a portion 

 of the carbonate ; the specific gravity is 2.63, the same as 

 that of a fine specimen of polished ferruginous odontolite 

 from the Himalaya ; it requires the heat of an oxygen blow- 

 pipe to fuse a fragment of it per se on platinum foil." 



The second fossil was found in the same sandy bed, at a 

 depth of 362 feet (PI. ix. fig. 2, a. b.) It was considered to 

 be part of the carapace or shield of a turtle, and to resem- 

 ble much some of the fragments found so plentifully among 

 the Jumna, Siwalik, and Ava fossils." It was mineralised 

 to the same extent as the first specimen, having a specific 

 gravity of 2.5, and losing under a red heat 10 per cent.* 



A third fragment of bone, unfortunately however so in- 

 jured by the auger as to make identification impossible, was 

 found at a depth of 375 feet. At 380 feet, there occurred a 

 thin layer, only two feet in thickness, of blue calcareous clay, 

 thickly studded with fragments of shells, and at 382 feet this 

 was succeeded by a layer of dark clay, composed almost en- 

 tirely of decayed wood. The appearance of the clay was 

 precisely similar to that of the black peat clay found at the 

 depth of from fourteen to thirty feet from the surface, and 

 formerly described. From the lower portion of it, several 

 fragments of coal, of excellent quality, were brought up. 

 The specific gravity of these curious and interesting 

 specimens was 1.20, and they exactly resembled the rol- 

 led pieces found now in the beds of mountain streams, and 

 which have always hitherto proved the means of leading to 



* Vide Note D. 



