GEOLOGICAL SUEVEY OF TFIE TERRITOEIES. 469 



3. ZapJirentis A small, slightly curved species, 



with fossula ventral. 



4. MicJwlinia Like M. tenuisepta, Phillips' (spe- 



cies.) 



5. Chcetetes . -. Slender ramose species 



6. Platycrinites {?) Arms and fragments of columns. 



7. Flatycrinites Haydeni, Meek.* 



8. Fentr&mites symmetricus, Hall ..As far as can be determined from 



the specimens, it seems to agree 

 well with P. symmetricus. 



9. FentremiUs Godonii, Defrance (?) 



10. Poteriocrinites MontanaensiSj 



Meek, t 



11. Erisocrinus (?) Body only, apparently of a species 



of this genus. 



12. Ftilodictya. 



13. FenesteUa Very delicate ; like F. pleheja, 



McCoy. 



14. Ftilopora. 



15. Strophomena analoga, Phillips. 

 IG. Orthis resupinatu, Martin, 



17. Chonetes A medium-sized, very finely stri9,ted 



species. 



18. Froductiis seynireticiilatus, Mar- 



tin, (species) A small, sulcated, strongly arcuate, 



and produced variety, apparently 

 of this species. 



19. Froduetm Altonensis, !N. & P. 



20. FfoductusscahriculuSjMiiTtin (?) 



21. FrodiLctns Frattemmus, Nor- 



wood. 



22. Frodu€tiis cora, d^Orhignj (^ .. .This agrees with European shells, 



referred to d'Orbigny's species; 

 but is more finely striated, and 

 much more produced, than d'Or- 

 bigny's type. 



23. Froductus A narrower, strongly arched, much 



produced species, marked % 

 small, very obscure concentric 

 wrinkles, and very small, slightly 

 elongated, raised points, that may 

 have supported minute spines. 



24. Eemipronites crenistria, Phillips, 



(species.) 



25. CamaropJioria Yery similar to C.glohuUna, Phillips. 



26. Athyris subtilita, Hall. 



* A small species, with a cup-shaped body, rounded below to a circular attachment 

 for the column ; body-plates smooth, or obscurely granular, and joined by slightly 

 grooved sutures; arms twenty, slender, each dividing once on the second piece above 

 their origin on the very small second radials, composed each of a single series of small 

 pieces, (as in P. nodohrachiatm, Hall, Iowa Keport, p. 542.) bearing pinnules alternately 

 on their inner lateral ends. 



t A small species with an elongate obconical body, composed of smooth plates, and 

 supported on a round column ; arms long, slender, apparently simple above their origin 

 on the last radials, and composed of small pieces, every third one of which bears, alter- 

 nately on opjjosite sides, a long pinnule. 



