100 Fossil Bones and Pseudo-Coprolites of the Crag. 



I. An ichthvo or fish-coprolite, from Tenby, presented to me 

 by Mr. Barker, when separated carefully from the surrounding 

 matrix^ was found upon analysis to contain — 



Water 11-400 



Carbonic acid ...... 16 '544: 



Sulphuric acid ...... 1'1S6 



Phosphoric acid 15-4016 



Lime 23-4914 



Oxide of iron . ..... 7*4737 



Alumina ....... 5*7033 



Silica and fluoride of calcium . . . 18-8000 



100- 



The matrix, on the contrary, contained only 0* 1263 per cent, 

 of phosphoric acid. 



lY. Fossil Bones. 



The majority of these remains which I have examined were 

 obtained from the bone quarries in the neighbourhood of Sutton, 

 in Suffolk, by the late Mr. Weddell, of Aldborough, by whom 

 they were kindly presented to me. 



The sample which this gentleman forwarded to me evidently 

 consisted principally of bones of extinct cetaceans ; and the fossils 

 could be readily divided into two classes, according to the appear- 

 ance they presented. The bones of the first class (a) were very 

 frangible, and possessed a somewhat porous or spongy texture, 

 caused by the existence of numerous minute cavities or air-tubes 

 in the substance of the bone ; v/hilst those of the second class (/3), 

 on the contrary, were very solid, and possessed a fibrous structure. 

 They were much harder than the former, and readily took a fine 

 polish. The air-cells in the latter were invisible to the unassisted 

 eye, and could only be detected by examining thin sections of the 

 bone under the microscope. 



a. Annexed are the results of two separate analyses of these 

 bones. 



phosj 



Water driven oft' at 30l)° to 350^ Fahr. 

 Water and organic matters expelled 



heat . 

 Carbonate of lime . 

 Carbonate of magnesia 

 Sulphate of lime . 

 Phosphate of lime, with some 



magnesia . . . 

 Perpliosphate of iron 

 Phosphate of alumina 

 Fluoride of calcium 

 Silicic acid « 



Nitrogen, per cent. 



late of 



2" 912 



3- 361 

 23-800 



0-286 



traces 



56-966 



4- 800 

 4-638 



undetermined 

 0*098 



Mean. 

 3-1360 



3- 8560 

 25-6000 



0-3285 

 0-257U 



52-8490 

 5-7000 



4- 0190 

 3-6570(?) 

 0-3620 



99-7645 

 undetermined. 



