112 



about i6 transverse rows, each row with about eight, exhibiting 

 a central round object surrounded by two circles, not always 

 perfect, the general effect comparable to Pleiirostichidium. 

 Filaments long, some reaching a length of i8 mm. (compare 

 Polysiphonia). 



The type is No. 15659, University of Colorado Museum; 

 Station 25, Kimball Creek. 



For further information about the Green River problem see 

 Henderson, "The Origin of the Green River Formation," Bull. 

 Amer. Assn. Petroleum Geologists, Vol. VIII, pp. 662-668. 

 1924. 



Boulder, Colorado. 



