in the Neighbourhood of Edinburgh. 219 
Besides the rays which have been assigned to the Gyracanthus, 
there exists a peculiar kind of Ichthyodorulite, comparatively 
small, and of an elegant form. But as so much more information 
is demanded relative to the placoidian animals to which they be- 
long, any drawings of them may be properly suspended until 
further remains turn up. 
I have now to state a very important analysis, undertaken. by 
Mr A. Connezt1, of the bony rays of the Gyracanthus formosus :— 
Phosphate of Lime with a little Fluoride of Calcium, 53.87 ; 
Carbonate of Lime 33.86; Siliceous matter 10.22; Potash and 
Soda, partly as chlorides, 0.71 ; Bituminous matter 0.54; Phos- 
phate of Magnesia, a trace ; Animal matter, a trace: Total 99.20. 
NOTES TO SECTION XIV. 
Mr Connett has compared the analysis which he has given of the bony rays of 
the Gyracanthus formosus with one by M. Dumentz of the bones of the recent pike. 
I shall throw these two analyses into a tabular form, for the sake of a more ready 
comparison. 
ANALYSIS OF THE BonEs OF THE PIKE, BY ANALYSIS OF A THorny Ray or THE GYRACANTHUS 
DumMxniL. FoRMOsUS, BY ARTHUR CONNELL, Esq. 
Phosphate of Lime, with a little 
Phosphate of Lime,. . . 55.26 Fluoride of Calcium, . . 53.87 
Phosphate of Magnesia, . . trace 
Potash and Soda, partly as Chlo- 
Traces of Soda, and loss, . . 1.82 Tides;izil So saancukem, okie ‘71 
Animal Matter, . . . . . 87.86 Animal Matter, . . . . . trace 
Carbonate of Lime,. . . . 6.16 Carbonate of Lime, . . . 88.86 
Siliceous Matter,. . . . . 10.22 
Bituminous Matter,. . . 54 
100.10 99.20 
If it be allowable to suppose that there was any original approximation in the qua- 
lity and quantity of chemical ingredients severally possessed by the bones of the 
pike and the fossil thorny rays of the Gyracanthus, which is rendered very probable 
by the proportion of phosphate of lime in each so nearly agreeing, the one analysis 
yielding 55.26 parts, and the other 53.87 parts in a hundred,—the following obser- 
vations occur. 
The fossil thorny rays contain a trace only of phosphate of magnesia, which has 
not been detected in the bones of the pike. 
Ee 2 
