LAURENTIAN AND EARLY PALEOZOIC. 



31 



of these, and Nathorst has confirmed this conclusion by 



aborate experiments on living animals, that these forms 



re really trails impressed on soft 

 liments by animals and mostly 

 by crustaceans. 



I agree with Dr. Williamson * 

 in believing that all or nearly all 

 the forms referred to Crossochorda 

 of Schimper are really animal im- 

 pressions allied to Nereites, and due 

 either to worms or, as Nathorst has 

 shown to be possible, to small crus- 

 ceans. Many impressions of this 

 dnd occur in the Silurian beds of 



tie Clinton series in Canada and 

 York, and are undoubtedly 



lere markings. 



It is worthy of note that these 



larkings strikingly resemble the so- 



alled Eophyton, described by Torell 

 from the Primordial of Sweden, and 

 by Billings from that of Newfound- 

 land ; and which also occur abun- 

 dantly in the Primordial of New 

 Brunswick. After examining a se- 

 ries of these markings from Sweden 

 shown to me by Mr. Carruthers in 



Dndon, and also specimens from Newfoundland and 

 large number in situ at St. John, I am convinced 



lat they cannot be plants, but must be markings of 



ae nature of Rhaldichnites. This conclusion is based 



n the absence of carbonaceous matter, the intimate 

 union of the markings with the surface of the stone, 



* " Tracks from Yoredale Rocks," " Manchester Literary and Philo- 

 phical Society," 1885. 



FIG. 9. Astropolitlion 

 Hindii, an organism 

 of the Lower Cam- 

 brian of Nova Scotia, 

 possibly vegetable. 



