I08 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 64 



Genotype. — IVeedia tuberosa, new species. 



Stratigraphic range. — Upper part of the Altyn limestone series 

 interbedded with sihceous and cherty layers. 



Geographic distribution. — Above Gunsight Pass, Glacier National 

 Park, Montana. This wiW probably be found to be a widely dis- 

 tributed form in the Algonkian formations. Heretofore such forms 

 have been passed over as of concretionary origin or as of secondary 

 siliceous deposits. 



Observations. — The generic name is given in recognition of the 

 work of Dr. Walter H. Weed among the Algonkian fomiations 

 of the Belt Mountains of Montana. 



WEEDIA TUBEROSA, new species 



Plate II. figs. I, 2 



The external characters of this species are well shown by figure 

 2. plate II. Also the structure of the tubercles as they have been 

 cut into by erosion so as to expose the irregular laminations and 

 in figure i the hollow interior, a feature so often seen in recent 

 " Lake Balls," plate 4. The main portion of the specimens repre- 

 sented by figure 2 is a thin encrustation on the upper surface of a 

 layer of limestone. 



Formation and locality, — {400) Algonkian: Siyeh limestone; 

 above Lake McDonald, south side of Gunsight Pass, Glacial National 

 Park, Montana. 



GREYSONIA, new genus 



Irregular, cylindrical or tubular growth with relatively thin walls 

 except at the union of three or more tubes, where the walls are 

 thickened as shown by figure 2, plate 17, and figure i, plate 18. The 

 tubes are large, irregularly rhomboidal or pentagonal in section 

 with the interior now filled in with a dark bluish-grey limestone. 

 The walls or partitions represent the deposit made by the algae and 

 are now a buft-colored and grey magnesian limestone. 



The ends of a group of the tubes filled in with the limestone 

 appear like a group of miniature basaltic columns (pi. 17, fig. 2), and 

 the base or lower side of the same tubes has irregularly oval and 

 round, concentrically marked forms that appear to be the filling of 

 the ends of the tubes. The walls of the tubes surrounding the ovals 

 and the basal ends are shown by figure 2, plate 18, and the broken 

 upper ends by figure 2, plate 17. The walls are arranged in echelon 

 and the fillings break out as plates of columns (fig. i, pi. 17). 



