VIl] SUPPOSED FOSSIL ALGAE. 149 



The statement is occasionally made that the numerous 

 fossil algae and the absence of higher plants in the older strata 

 justify the description of the oldest rocks as belonging to the 

 * age of algae.' Such an assertion rests on an unsound basis, and 

 is rather the expression of what might be expected than what 

 has been proved to be the case. The oldest plants with which 

 we are at all closely acquainted are of such a type as to forcibly 

 suggest that in the lowest fossiliferous rocks we are still very 

 far from the sediments of that age which witnessed the dawn 

 of plant life. 



Many of the obscure markings on rock surfaces which have 

 been referred to existing genera of algae or described as new 

 genera, are much too doubtful to be included even under such a 

 comprehensive name as Algites. Space does not admit of 

 further reference to determinations of this type which abound 

 in palaeontological literature. 



It would be very difficult to produce satisfactory evidence 

 for the algal nature of many of the supposed fossil algae from 

 Cambrian rocks ^ ; there has been a special tendency to recognise 

 algal remains in the oldest fossiliferous strata, due in part no 

 doubt to the fallacy that in that period nothing higher than 

 Thallophytes is likely to have existed. The so-called Phycodes 

 referred to by Credner^ as characteristic of the Cambrian rocks 

 of the Fichtelgebirge {" Phycoden-Schiefer ") is probably of 

 inorganic origin, and comparable to the genus Vexillum of 

 Saporta^ and other writers, which Solms-Laubach has described 

 as being formed every day in the soft mud of our ponds where 

 local currents are checked by branches and other obstacles*. 

 There are several good specimens of Phycodes in the Berg- 

 akademie of Berlin and in the Leipzig Museum which, I believe, 

 clearly demonstrate the absence of all satisfactory evidence of 

 an algal origin. 



We may next pass to a short description of a few repre- 

 sentative types of algae, which may reasonably be classed under 



1 Cf. Matthew, G. F. (89). Hall called attention in 1852 to tlie prevalent 

 habit of describing 'algae' from the older strata, without any evidence for a 

 vegetable origin. (Hall [52] p. 18.) 



2 Credner (87) p. 431. » Saporta (84) p. 46, PI. vii. 

 * Bolms-Laubach (91) p. 51. 



