62 FOSSIL MEDUS 4%. 
1. Against the first he urges the multiplicity of the strize, their clear- 
ness, their strictly rectilinear direction, but more especially the fact that 
they not only touch but intermingle in such a way that one passes above or 
beneath the other; this he claims could not occur with simple tracks. 
2. Against their being trails made by medusze, or algee being dragged 
over the surface, he adduces the facts that they extend in so many different 
directions, are so clear, and are often in the shape of veritable cylinders. It 
is, further, incomprehensible that the Cambrian should have the monopoly 
of such effects. Lastly, the objection offered in the former case, that the 
trails intermingle, holds good here. 
3. On the supposition that these are plant remains, all the above facts 
are perfectly natural. The striae, he says, are not nerves, but superficial 
longitudinal ridges, not without analogy in Bilobites and Taonurus. He 
thinks that the markings may be both trails and impressions, the well- 
defined and solid ones being impressions, the others trails of fragments swept 
about on the sea bottom. 
In reply to Nathorst, that these never occur with vegetable remains, 
Saporta describes Hophyton bleicheri n. s. from the environs of Vailhan, 
which agrees with Eophyton in every way, yet shows dark discoloration 
due to plant substance.' 
In an earlier paper Messrs. Saporta and Marion said: * 
It appears impossible to admit Nathorst’s explanation and not to recognize in 
the remains described by Torell a vegetable organism similar to others passed in 
review. though different in genus, yet beyond doubt belonging to the same family. 
There are shreds, detached fragments, preserved in demirelief and occupying the under 
surface of Silurian slabs in the greatest disorder. Some of these tatters are flat, 
ribbon-like, others have a cylindrical form, often appearing lacerate; all having their 
surface furrowed by numerous longitudinal striz, parallel and regularly disposed. 
Chance alone could not have produced a similar arrangement, no more than the relief 
visible in certain of the fragments. 
Whether Dr. Nathorst is correct in interpreting Eophyton as made up 
of trails produced on fine sand or mud by medusz may possibly be open 
to question; but it is true, as he states, that such forms occur from the 
Cambrian to the Trias, and to my mind it is quite probable that im some 
instances they may have originated as he suggests. As regards others, 
1A propos des algues fossiles, Paris, 1882, p. 63. 
2L’Evolution du regne végétal; Cryptogames, 1881, p. 83. 
