168 



Forty- SIXTH Report on the State Museum. 



11. Monomerella Egani, Niagara 



group 175 



12 . Rhinobolus Davidsoni, Niagara 



group 176 



13. Siphonotreta (?) Minnesotensis, 



Trenton limestone. 177 



14 . Orbiculoidea (Schizotreta) ora- 



lis, Trenton limestone 177 



15. Orbiculoidea numulus, Lower 



Helderberg group 178 



1 6 . Orbiculoidea Herzeri , Waverly 



group 178 



1 7 . Lindstroemella aspidium , Ham- 



ilton group 179 



18. ScliizocraniaSchucherti, Hud- 



son River group 179 



19 . Schizocrania (?) Helder- 



bergia, Lower Helderberg 

 group 179 



20 . Crania agaricina, Lower Held- 



erberg group 180 



21 . Crania pulchella, Lower Held- 



erberg group 180 



23. Crania granosa, Hamilton 



group 180 



23. Crania favincola, Hamilton 



group 181 



24. Craniella Ulrichi, Trenton 



group .... 181 



25. Orthis? Saflfordi, Trenton 



group 340 



26. Orthis? Holstoni (Safford), 



Trenton group 340 



27. Orthis (Plaesiomys) loricula, 



Trenton group 341 



28. Orthis (Dalmanella) arcuaria, 



Hudson River group 341 



29 . Orthis (Dalmanella) superstes, 



Chemung group 342 



30 . Orthis (Rhipidomella) Oweni, 



Keokuk group 342 



31. Orthis (Schizophoria) senecta, 



Clinton group 343 



32. Strophomena Conradi, Tren- 



ton group 344 



33 . Strophomena Winchelli, Tren- 



ton horizon 344 



34. Orthothetes desideratus, Wav- 



erly group 345 



35. Derbya ruginosa, Keokuk 



group 346 



36. Derbya? costatula, Chester 



group 346 



37. Derbya Broadheadi, Coal 



Measures 347 



38. Derbya Bennetti, Coal Meas- 



ures 348 



39. Derbya cymbula, Coal Meas- 



ures 348 



40 . Derbya affinis, Coal Measures. 349 



41 . Derbya (?) biloba, Coal Meas- 



ures 350 



42 . Strep torhynchus Ulrichi , Ches- 



ter group 351 



43. Christiania subquadrata, Low- 



er Helderberg group 351 



44. Leptsenisca adnascens, Lower 



Helderberg group 352 



45. Leptsenisca tangens. Lower 



Helderberg group 352 



46. Chonostrophia Helderbergia, 



Lower Helderberg group . . . 353 



47. Strophalosia Rockfordensis, 



Upper Devonian 358 



