in one place The dip of the strata is marked, and the formation may be from 20 to 25 foot thick again by the Camden chert. The latter cannot be seen except by the mark of broken chert on the two sides. At Allens mill on the Birdsey occurs an exposure of Menisid cus bristae followed by Zone Helduby. I saw a few Zt. Orthis and several two species and some fragments of that peculiar bush crinoid root. That the Meniscus bristae also occurs here is shown by the presence of Astraeospongiae. On Wolf Creek the Zone Heldu- bury is mainly a shale and a few thin beds of limestone. One portion has considerable limestone and it