PRE-CARBONIFEROUS FLOEAS. 



441 



tlie group of the " Fucoids," under the generic titles of Palmo- 

 phycus, Licrophyous, ButhotrepMs, Fhytopsis, Sphenothalkis, 

 &c. Some of these appear to be nothing more than the 

 tracks of Annelides. Others appear to be unquestionable 



Fig. 696. — Fragment of Eopliyton Linneamim. Lower Cambrian. 



plants ; but nothing positive can be stated as to their 

 affinities. They may be Algcc, or they may belong to plants 

 higher in the vegetable scale. Subjoined is an illustration of 

 a characteristic Canadian species described by Mr Billings 

 (fig. 697). 



Here, also, we may briefly consider certain remains dis- 

 covered by the author in the Skiddaw Slates of the North 

 of England, a formation which is now generally regarded as 

 belonging to the lowest division of the Lower Silurian series 

 of Britain. The remains in question were originally referred 

 provisionally to the genera Butliotrephis and Eojpliyton, and 

 the fossils which led to the former determination appear to 



