THE CAMBRIAN PERIOD. 81 



to be rather referable to the tracks and burrows of marine 

 worms. The first-mentioned of these formations has also 

 yielded the curious, furrowed and striated stems which have 

 been described as a kind of land-plant under the name of 

 Eophyton (fig. 28). It cannot be said, however, that the vege- 



Fig. 28. Fragment of Eophyton Linneanum, a supposed land-plant, Lower 

 Cambrian, Sweden, of the natural size. 



table origin of these singular bodies has been satisfactorily 

 proved. Lastly, there are found in certain green and purple 

 beds of Lower Cambrian age at Bray Head, Wicklow, Ireland, 

 some very remarkable fossils, which are well known under the 

 name of Oldhainia, but the true nature of which is very doubtful. 

 The commonest form of Oldhamia (fig. 29) consists of a 

 thread-like stem or axis, from which spring at regular intervals 

 bundles of short filamentous branches in a fan-like manner. 

 6 



