Organic Remains of Burdiehouse. 



289 



The bony fin rays, Dr Hibbert informs me, belong to a fos- 

 sil fish, which has been designated by M. Agassiz, Gyracanthus 

 formosus, and is supposed to approach in character to the Ces- 

 tracion of New Holland. 



20.14 grains of these rays were found to be composed as 

 follows : 



Phosphate of Lime, with a little Fluoride of Calcium, 



Carbonate of Lime, .... 



Siliceous Matter, .... 



Potash and Soda, partly as Chlorides, 



Bituminous Matter, .... 



Phosphate of Magnesia, 



Animal Matter, .... 



Trace 

 Trace 



53.87 



33.86 



10 22 



.71 



.54 



99.20 



The siliceous matter contained in the fin rays was left undis- 

 solved when they were treated with the acid, and presented the 

 appearance of small solid cylindrical masses, grouped longitudi- 

 nally together. These siliceous portions may be observed in the 

 solid bone itself, before it is acted on by the solvent, and evident- 

 ly suggest the idea of longitudinal cavities in its substance, which 

 had become filled with infiltrated siliceous matter. 



The scales analyzed were those of the fossil genus of fish to 

 which the name of Megalichthys has been given by M. Agassiz. 

 The great fossil teeth found at Burdiehouse belong to the same 

 animal. It is supposed to approach in its characters to the Lepi- 

 sosteus, or Lepidosteus of Agassiz. The scales had the usual 

 fine lustre, and smooth but delicately punctured surface. They 

 were generally about three-fourths of an inch long, by some- 

 what less in breadth. 



15.86 grains of these scales submitted to analysis gave the 

 following result : 



VOL. XIII. part i. oo 



