374 GEOLOGICAL SURVEY OF THE TERRITORIES. 



ji2ime UucladocrinuSj in allusion to its very numerous. branches 

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

 entire series. 



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



Bridger Butte, near Fort Ellis. 



These fragments probably belong to several species of dif- 

 ferent genera. 



11. Folypora; Twin Springs and Junction Divide. 



12. Fenestella (allied to F. multiporata, 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. Ptylopora 'j Devil's Slide, Montana. 



16. Semipro7iites (either S. crassius, or H. crenistria) ; mountain, near 



Junction Divide, head Medicine Bow Creek, and Bear Eiver 

 Mountains, opposite Eandolph. 



17. Cho7ietes ; Twin Springs. 



18. Froduetiis punctatifsP, head of Alder Gulch, Virginia City, Motana. 



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



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



21. Froductus longispimis, Sowerby ? ; Junction Divide. 



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



23. Froductus semireticulatus ^^lnYtiii', mountains near Junction Divide, 



head of Medicine Creek. 



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



Creek. 



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



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



Creek, near Divide. 

 *21. Spirifer (a smalhjr 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. contracta^ M. & W.; half-way between 



Mantua and Cache Creek. 



30. Spiriferinaj 1 (like S. octoplicata^ Sow.) ; Twin Springs. 



31. EiLomplialus ; Twin Springs. 



JURASSIC SPECIES. 



1. Rliync1i07iella ; shore of lake, twelve miles from Fort Ellis. 



2. Lingula ; Lincoln Valle^^, near Fort Hall. 



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

 4:.<*Gryphcca (small, imperfect specimen) ; Lincoln Valley, near Fort 



Hall. 



5. Camptonectes hellistriata, M. & H. j shore of lake, twelve miles from 



Fort Ellis. 



6. Entolium cingulatus^ Phillips *? (sp.) ; shore of lake, twelve miles 



from Fort Ellis. 



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



Fort Ellis. 



8. Aviculopecten {Fseudomonotis 1 ) IdahoensiSy 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. 



