at the Junction of Sienite with Dolomite. 129 



specimens (9, 10, 11,) for examination at leisure, a circum- 

 stance I now regret, as it deprived me of the opportunity of 

 studying so minutely as I should otherwise have done, its re- 

 lation to the surrounding rocks. It was, however, not united 

 either to the sienite or dolomite en masse. The former, as it 

 approached the dolomite, became gradually more and more 

 intermixed with layers of the mealy substance above de- 

 scribed, lying parallel with the general direction of the plane 

 of junction, and in the midst of these layers occurred the la- 

 mina of serpentine. Below this again was found the mealy 

 substance in a state of greater purity, but still not free from 

 layers of the sienitic matter, which however gradually disap- 

 peared, leaving it nearly pure up to its contact with the dolo- 

 mite. The whole transition took place within a thickness of 

 about eighteen inches or two feet. 



. These specimens are now (the moisture being exhaled) not 

 to be mistaken, and have all the characters of the best defined 

 serpentine — the greasy lustre, unctuous feel, and irregular 

 fibrous appearance of their surfaces, the dulness of their cross 

 fracture, translucency at the edges, and variation of colour 

 from dark to light green. I am not aware of the occurrence 

 of any serpentine rock in the neighbourhood. 



1 shall not attempt to reason on this fact, which presents 

 considerable analogy with that recently described by Dr Mac- 

 Culloch, as occurring at the junction of a trap vein with lime- 

 stone in Scotland, (vide vol. i. of this Journal, p. 1,) but 

 content myself with submitting the specimens, with this very 

 imperfect account, to the judgment of better geologists than 

 myself. 



■ .... i -~ ■ . ■ . 



Art. XXV 1. — Notice of' the Remains of an Animal resemb- 

 ling the Scandinavian Elk, recently discovered in the Isle of 

 Man ; with Suggestions on the Importance of distinguish- 

 ing this Animal from the Fossil Irish Elk. In a Letter to 

 Dr Brewster, from Samuel Hibbert, M. D. F. R. S.E. 

 and M.G.S. Secretary to the Society of Scottish Antiquaries. 

 My Dear Sir, 

 1 transmit you the following communication, which must be 

 considered as an appendix to my paper inserted in the early 

 VOL; III. NO. t. JULY 1825. i 



