146 Selwyn — Tracks in rocks of the Animikie group. 



Another piece of flag has an impression similar to some 

 which have been referred to Taonurus, etc., but which I think 

 are not seaweeds. These as well as Eophyton appear to me to 

 be tracks made in the mud by marine animals. 



This Taonurus like impression exhibits a group of striae con- 

 verging from a furrowed margin, and becoming more or less 

 parallel and approximate. The markings are such as would 

 be made by an animal having numerous tentacles or arms, 

 furnished with hooks or horny protuberances at the extremity. 

 If such arms were spread and pressed down upon the muddy 

 bottom, and gradually drawn together as the animal moved 

 onward, they would make such markings as are found on this 

 piece of flagstone. 



A radiate animal might make a track like this, and since 

 remains of such creatures (Acalephs and Echinoids) have been 

 reported from a lower horizon in the Cambrian rocks of 

 Sweden, than that which, in this region, carries the resembling 

 impressions, one may conjecture that these tracks have been 

 made by a radiate animal of some kind. 



The resembling impressions at St. John are found on the 

 layers of fine sandstone and shale which belong to Bands a and 

 c of Division 2 of the St. John group. The equivalent of 

 Division 2 in Europe is the Olenus Zone, the Maentwrog and 

 Ffestiniog groups of Wales. 



Our best examples show spindle-shaped furrows, radially ar- 

 ranged near the margin of the track, larger and flatter in the 

 bottom than those of the Animikie example. In ours the 

 furrows narrow into striae which converge and become nearly 

 parallel. The Animikie form shows markings made by three 

 groups of tentacles, all moving in nearly the same direction, 

 but not applied to the sea-bottom simultaneously. 



I propose for such tracks the name Taonichnites. 



Another piece of flagstone from the Animikie group has 

 markings due to an animal entirely different from that which 

 made the markings above described. These are straight and 

 parallel, and in sets which often cross at a small angle. They 

 look exceedingly like the glacial striae found on rock surfaces, 

 in which, in a similar manner, the different sets interfere with 

 each other. 



I have studied the variations of these markings found in the 

 rocks at St. John, and think they indicate an animal which 

 had arms placed on each side of the body, at least three in 

 each set, and that these arms were beset with small spines or 

 hooks. When moving along the bottom the animal threw its 

 arms backward and outward and then drew them forward, thus 

 making as it advanced the straight parallel striae so character- 

 istic of the principal part of its track. 



