374 GEOLOGICAL SUEVEY OF THE TEEEITOEIES. 



name Micladocrinus, in allusion to its very numerous branclies 

 or arms, of wliicli there must be not less than 160 to 200 in the 

 entire series. 



10. Grinoid fragments; Twin Springs, Sage Creek, Montana; and 



Bridger Butte, near Fort Ellis. 



These fragments probably belong to several species of dif- 

 ferent genera. 



11. Polypora ; Twin Springs and Junction Divide. 



12. Fenestella (allied to F. onultiporata, McCoy) ; Devil's Slide and 



head of Black-Tail Deer Creek, Montana. 



13. Fenestella (two or three species) ; near Junction Divide. 



14. Ptylopora; Devil's Slide, Montana. 



15. Ptijlopora ; Devil's Slide, Montana. 



16. Hemipronites (either S. crassius, or H. crenistria) ; mountain, near 



Junction Divide, head Medicine Bow Creek, and Bear Eiver 

 Mountains, opposite Eandolph. 



17. Chonetes; Twin Springs. 



18. Productus punctatml ; head of Alder Gulch, Yirginia City, Motana. 



19. Productus ; head of Black-Tail Deer Creek. 



20. Productus (fragments of a very finely striated species) ; Dry Creek. 



21. Productus longispinus, Sowerby 1 ; Junction Divide. 



*22. Productus ; half-way between Mantua and Cache Valley. 



23. Productus semireticulatus, Mavtin; mountains hear Junction Divide, 



head of Medicine Creek. 



24. BhyncJwnella ; mountains near Junction Divide, head of Medicine 



Creek. 



25. Atliyris suhtilila, H. ? ; mountains near Junction Divide. 



26. Spirifer (a large species like S. Logani, Hall) ; Medicine Lodge 



Creek, near Divide. 

 *27. Spirifer (a smaller species, more extended on hinge-line) ; half-way 



between Mantua and Cache Valley. 

 28. Spirifer ; Bridger's Butte, near Fort Ellis. 

 *29. Spirifer fMartiniaJ, like M. coiitracta, M. & W.; half-way between 



Mantua and Cache Creek. 



30. Spiriferina,% (like S. octoplicata, Sow.).; Twin Springs. 



31. EuompJialus; Twin Springs. 



JUEASSIC SPECIES. 



1. Bhynclionella ; shore of lake, twelve miles from Fort Ellis. 



2. Lingnla ; Lincoln Valley, near Fort Hall. 



3. Ostrea (mere fragments) ; Lincoln Valley, near Fort Hall. 

 4:.'^Gryphcca (small, imperfect specimen); Lincoln Valley, near Fort 



Hall. 



5. Camptonectes delUstriata, M. & H. ; shore of lake, twelve miles from 



Fort Ellis. 



6. Fntolium cingulatus, Phillips ? (sp.) ; shore of lake, twelve miles 



from Fort Ellis. 



7. Gervillia (an imperfect valve) ; shore of lake, twelve miles from 



Fort Ellis. 



8. Aviculopecten {Pseudomonotis 1 ) Idalioensis, Meek. 



Shell suborbicular, very slightly oblique; hinge distinctly 

 shorter than the valves. Left valve rather compressed ; pos- 

 terior ear very short or nearly obsolete, and scarcely angular 

 at the extremity, the posterior margin below being convex iu 



* These may possibly be Devonian. 



