454 GEOLOGY OF THE YELLOWSTONE NATIONAL PARK. 



HYOLITHES Eichwald. 



Hyolithes primordialis Hall. 



PL LXIII, tigs. 2, 2a. 



Theca primordialis Hall, 1861: Ann. Kept. Progress Geol. Surv. Wisconsin, p. 48. 



Hall, 1862: (ieol. Eept. Wisconsin, Vol. I, p. 21, fig. 5. Hall, 1863: Sixteenth 



Ann. Eept. New York State Cab. Nat. Hist., p. 135*, PI. VI, figs. 30,31. 

 Pugiunculus primordialis Hall, 1863: Ibid., p. 135*. 

 Theca (Pugiunculus) gregaria M. and H., 1861: Proc. Acad. Nat. Sci. Philadelphia, 2d 



series, Vol. V, p. 436. M. and H., 1864: Pal. Upper Missouri, Pt. I, p. 5. 

 Hyolithes {Theca) primordialis Hall and Whitfield, 1873: Twenty-third Ann. Eept. 



New York State Cab. Nat. Hist., p. 242, PI. II, fig. 3. 

 Hyolithes primordialis ? White, 1874: Expl. Surv. West 100th Merid., Prelim. Eept., 



Invert. Foss., p. 6. 

 Hyolithes primordialis White, 1S75 : Ibid., Final Eept., Vol. IV, Pt, I, p. 37, PI. I, figs. 



5«-e. Whitfield, 1883 : Geol. Wisconsin, Vol. IV, p. 175, PI. I, fig. 12. Walcott, 



1884 : Mou. U. S. Geol. Surv., Vol. VIII, Pal. Eureka District, pp. 23, 24. 



Forms of this species occur at several localities, and are identical with 

 those found in the Middle Cambrian St. Croix sandstone of Wisconsin. 

 They vary in length from 1 to 5 cm. The young individuals when grouped 

 together in the limestone are very closely related to, if not identical with, 

 Theca gregaria. 1 The type specimens of the latter were found near the 

 head of Powder River in the Bighorn Mountains of Idaho Territory, now 

 in Wyoming. 



Formation and locality: Middle Cambrian, Flathead formation, Crow- 

 foot section, Gallatin Range; Clark Fork Valley, south side, between 

 Lods-e Pole and Reef creeks; and bluff on south side of Pebble Creek, 

 north of saddle to Soda Butte Creek, Yellowstone National Park. 



AGNOSTUS Brongniart. 



Agnostus raTERSTRicTus White. 

 PI. LXIII, figs. 3, 3a. 

 Agnostus interstrictus White, 1874: Geol. and Geog. Expl. West 100th Merid., Prelim. 

 Eept., Invert. Foss., p. 7. White, 1875: Ibid., Final Eept., Vol. IV, Pt. I, 

 p. 38, PL II, 5«, b. Walcott, 1886 : Bull. U. S. Geol. Surv. No. 30, p. 149, PI. 

 XVI, figs. 6, 6a. 



A comparison of the specimens from the Gallatin Range with the type 

 specimens from the Springhouse Range of Utah leads to the conclusion 



1 Pal. Upper Missouri, Pt. I, 1864, p. 5. 



