139 



*Thallus frondose, continuous, spreading widely in the same plane, and 

 consisting, as now preserved, of a thin, uniformly flat expansion, devoid 

 of midrib or veins, which is doubly deeply and widely trifurcate, with 

 the secondary divisions again once or twice cleft at their summits ; the 

 undivided and partially divided portions narrow below, widening above 

 and widest at the commencement of each division, averaging from three 

 to four millimetres in breadth in the narrowest places, and from fourteen 

 to fifteen mm. in the widest. Base of attachment unknown; minute 

 structure not preserved. 



Inmost or Birch Island, Kinwow Bay, Lake Winnipeg, T. C. Weston, 

 1884: four good specimens, consisting of well defined, rather dark brown, 

 ferruginous impressions upon pieces of pale buff-coloured limestones, and 

 seven similar but very imperfect ones. 



In the present state of our knowledge, it would seem that Bythotrephis, 

 (Hall)t can scarcely be satisfactorily distinguished from Chondrites 

 (Sternberg). Goeppert,J though he retains the name Bythotrephis for B. 

 flexuosa and B. succulenta, as described and figured by Hall, is careful to 

 state that he does so provisionally, on account of the absence of satis- 

 factory evidence on this point, and says that the only difference between 

 Bythotrephis and Chondrites is the flatter habit of the thallus of the 

 former, a character which, he adds, is not always seen in Hall's flgures of 

 species of Bythotrephis. Geinitz and Liebe§ say that no essential differ- 

 ence can be recognized between the two genera, and claim that Goeppert 

 also is of the same opinion. 



*Most of the descriptions of species that have been previously described by the 

 writer in other publications, have been either partially or wholly rewritten for this 

 Report. 



t Originally spelled Buthotrephis. 



X Ueber die Fossile Flora der Silurischen, der Devonischen und Unteren Kohlen- 

 formation oder des Sogenannten XJebergangsgebirges, 1859, p. 452. 



§ Ueber ein ^Equivalent der Takonischen Schiefer Nordamerika's in Deutschland, 

 &c., p. 18. 



