latter look very much like I. labiatus. They occur in calcareous bands about half way down the west slope of the upper sandstone member of the Dakota ridge. Beginning at top of ridge we find, not the usual hard, thick bedded sandstone, but a softer thin bedded sandstone, weathering rapidly, perhaps 20 feet thick with numerous fucoids ? Below this are possibly 50 feet of sandy shales, including fossiliferous calcareous bands, the pure sands not at all calcareous. Below this 30 ft. or more of noncalcareous, thin bedded black and gray shales, much like those of the Benton and Pierre, non-fossiliferous extending to bottom of lateral gulch. Below this, on east slope of west ridge, friable sandstone. This is underlaid by typical hard “Dakota” sandstone and conglomerate which forms the crest of the second ridge thus: ((drawing in field book)). Nearly a mile north of the road there is either a fault or fold in the Dakota, N and S, thus (( drawing in field book)). Exposures too poor to determine the exact condition.
