Chemistry a)i<l Pin/sirs. 147 



The manner in which it spread its arms was therefore fclie 

 reverse of that pursued by the creature which made the 

 Taonichnite track. 



After a consideration of the various forms of this track and 

 the circumstances under which it occurs, I can think of no 

 animal except one related to the Squid or Calamary capable of 

 making it. 



These impressions are found near the base of the St. John 

 up and through its Division 2, or in other words, in the 

 blenellus and (Menus Zones; and 1 would suggest for them the 

 name Ctenichnites, A fuller description of these tracks with 

 figures will be given in a paper now in preparation for the 

 Royal Society of Canada. 



Both of the forms of track above described belong to shallow 

 sandy and muddy shores, and must have been comparatively 

 common on the Cambrian coasts, where sand and mud beds 

 alternated. On the sands unless they are muddy sands the 

 tracks were only faintly made, but in the soft fine mud they 

 are most prominent. They are most easily recognized by the 

 mould of the track on the under side of beds of sandstone 

 whose sand has been deposited in and over the impressions the 

 animal made in the mud beneath. These moulds are often 

 strikingly distinct, more so than the tracks themselves. 



Eophyton (properly Eoichnites) bears considerable resem- 

 blance to Ctenichnites, but in the examples of Eophyton which 

 I have seen, we seldom fail to recognize a depressed groove or 

 broad shallow furrow, which Torell appears to have mistaken 

 for the stem or trunk of a plant. 



I should add that in the Ctenichnites of the Acadian Cam- 

 brian rocks as known to me the striae are coarser and more 

 widely spread than those of the Animikie example which you 

 sent me. 



I remain, yours, etc., 



G. F. MATTHEW. 

 St. John, New Brunswick, January 3, 1890. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. On the Periodic Laic. — In his Faraday lecture before the 

 Chemical Society, Mendeleeff took for his subject the periodic 

 law of the chemical elements. In March, 1869, he had enunci- 

 ated his conclusions as follows : (1) The elements if arranged ac- 

 cording to their atomic masses, exhibit an evident periodicity of 

 properties ; (2) elements which are similar as regards their chem- 

 ical properties, have atomic masses which are either of nearly the 



