112 DEPARTMENT OF THE INTERIOR 



2 GEORGE V., A. 1912 



14. Spirif er utahensis. Shows a plication in the sinus. Ventral valve 



with twisted beak. This is the only specimen found of Spirifer 

 utahensis in Dr. Daly's collections. This is eminently character- 

 istic and abundant in the Jefferson limestone of the United States. 



15. Camarotoecliia, sp. 



16. Pleurotomaria, (probably a Liospira or allied form), flat-valved. 



17. Gasteropod. 



18. Aviculoid (?) shell, too imperfect for identification. 



19. Orthoceras, sp. Portion of shell representing some twenty septa 



of a test rapidly increasing toward the aperture.' 



About 800 feet higher up in the apparent monocline other fossils, taken at 

 station No. 1218, are named by Dr. Ami as follows: — ■ 



' Station No. 1218. — 150 yards north of Boundary line, eastern edge of the 

 Tobacco. Plains. 



A dark gray coralline limestone; very similar to the characteristic rock of 

 the Jefferson limestone of Montana. The identical association of forms and 

 the general physical properties of the limestones of British Columbia and 

 Montana are remarkable and leave no doubt as to the identity of the horizons. 



Age: Upper Devonian. 



Formation: Jefferson limestone. 



Genera and species: 



1. Stromatoporoids. Exhibit concentric laminae, cf. A. variolare; large 



and small masses. 



2. Favosites, sp. A form very close to, if not identical with, F. 



limitaris, Rominger. 



3. Favosites, sp. A form consisting of much larger fronds and smaller 



corallites than those of last species. (New species?) 



4. Favosites, sp. Cf. F. limitaris, Rominger. 



5. Brachiopod. ribbed; too imperfect for identification. 



6. Atliyris, sp. Cf. A. parvida, very obscure example of what appears 



to be this species. 



7. Athyris. Small species resembling A. parvula W. 



8. Spirifer englemani. The same form occurs also in Montana. 



9. Spirifer. Cf. S. argentarius. The radiating lines which are pro- 



minent on the fold constitute a rather distinctive feature in 

 this species.' 



The quartzite is tentatively assigned to the Devonian. Mississippian 

 horizons are possibly represented in the fault-block, for the collection of fossils 

 has been by no means exhaustive. The greater part of the limestone is to be 

 correlated with the Jefferson limestone of Montana. 



