201 



26. Isotelus gigas de Kay r-e 



27. Mesotrypa regularis (Foorcl) a 



28. Nematopora ovalis Ulrieli r-c 



29. Pachydictya sp r 



30. Platystrophia trentonensis n. sp .r-c 



31. Plectambonites serieeus (Sowerby) a 



32. Plectorthis plieatella (Hall) r 



33. Prasopora simulatrix Ulrich e 



34. Primitia mammata Ulrieli r-c 



35. Protocrisina exigua Ulrich a 



36. Rhinidictya mutabilis (Ulrich) a 



37. Rhinidictya rnutabilis major (Ulrieli) c 



38. Rhinidictya paupera Ulrich . c 



39. Rhynchotrema increbescens (Hall) r-c 



40. Schizocrinus nodosus Hall c 



41. Stictoporella cribrosa Ulrich e 



42. Stictoporella angularis Ulrich e 



43. Strophemna incur vata (Shepard) aa 



44. Tetradella subquadrans Ulrich r-c 



45. Trematis terminalis (Emmons) . r 



46. Turrilepas canadensis Woodward r-c 



47. Zygospira recurvirostris (Hall) r-c 



Mobpht Creek Section. 



About one and one-half miles down the Mohawk river from Port Jack- 

 son on the south side of the river is an outcrop of the Trenton, Black river 

 and Calcif erous (Tribes Hill and Little Falls dolmite) . 



The basal Trenton resting on the Black river in this outcrop contains the 

 pebble-like masses of Stromatoporoids (Stroma tocerium canadense Nichol- 

 son and Murie) as at Pattersonville, and consisting of compact beds of dark 

 crystalline limestone in which Strophomena abound. The difference in ap- 

 pearance of this section and that at Pattersonville quarries is chiefly due to 

 weathering. 



The Black river is underlain by a compact, nearly unfossilif erous blue 

 limestone, which is probably the Birdseye (Lowville). 



Collections were made only from the thin-bedded Trenton above the crys- 

 talline bed. Mesotrypa and Prasopora are most abundant about ten feet be- 



