68 THE CANADIAN NATURALIST. [Vol. viL. 



Ai'enicoUfes, Salter. 



This genus may be held to include cylindrical burrows of 

 worms with or without marks of minute setae. They occur in^ 

 rocks of all ages, and are especially abundant in the Lower 

 Carboniferous series of Half-way River, Nova Scotia, and in the^ 

 Upper Coal-formation at Tatamagouche in the same province ;. 

 those at the latter place showing minute scratches produced by 

 the setge of the worms,* With the ordinary form at Hortort 

 there occur very long and slender, thread-like forms of the same 

 nature with those to which the name Nemertltes has been given. 



I have long been of opinion that many of the cylindrical 

 markings which have been described as plants under the names 

 PalcBOchorda, Bittliotrej^liis, Palceopliycus, Arthi'OjyJii/cus, &c.y 

 are burrows of this kind, but the main difficulty seemed to be to- 

 account for their branching in a radiate or palmate manner. I 

 have recently met with specimens from the Primordial and 

 Carboniferous which seem to explain this. They show a central 

 hole or burrow from which the animal seems to have stretche($ 

 and withdrawn its body in different directions, so as to give an 

 appearance of branching and radiation, possibly due merely to 

 the excursions of the same worm from the mouth of its burrow. 



No distinct examples of the Primordial and Silurian worm- 

 trails known as Nereites, Mijrianites and Crossopodia, have yet 

 occurred to me in the Carboniferous. 



Dipliduiites, Dawson. 



In the Journal of the Geological Society for 1861, I described 

 a remarkable series of impressions found at the Joggins in the 

 Coal-formation, on the surface of a sandstone holding footprints 

 of reptiles. It consists of two rows of strongly marked depres- 

 sions about one inch long and a quarter of an inch broad (fig. 3). 

 These marks are placed close together in each row, and the rows 

 are six inches apart, while the space between is somewhat smoothed" 

 as if by a flat body drawn over it. The general appearance is 

 somewhat that which would be produced by a heavy-laden toy 

 cart six inches wide, and with broad wheels, notched or cogged 

 at the edges, if dragged over firm sand. I suggested, in the 

 paper above mentioned, that these singular markings might have 



* Journal of the Geological Society, vol. 11. 



