7 29 Modiomorpha mytiloides and Orthoceras cratulum, Hall. Hamilton group. Pratt's Falls, N.Y. 30 Orthoceras subulatum, Hall. Hamilton group. Pratt's Falls, Onondaga Co., N.Y. 31 Siphuncle of Cyrtoceras subrectum, Hall. Shaly limestone Lower Helderberg group. Clarksville, N.Y. 32 Strophodonta leavenworthiana, Hall. Shaly limestone Lower Helderberg group. Clarksville, N.Y. 33 Strophodonta leavenworthiana, Hall. Shaly limestone Lower Helderberg group. Clarksville, N.Y. 34 Proetus rowii, Green Hamilton group. Hamburg, New York. 35 Phacops rana, Green. (two specimens together) Hamilton group. Hamburg Erie Co., N.Y. 36 Leperditia alta, Conrad. Tentaculite limestone Lower Helderberg group. Jerusalem Hill, Herkimer Co., N.Y. 37 Orthoceras perstriatum, Hall. Shaly limestone Lower Helderberg group. Clarksville, N.Y. 38 Orthoceras n. sp? cut and polished to show siphuncle. Hudson river group, from the Drift at Ann Arbor Michigan 39 Lichas (psyidium and counterpart) Shaly limestone Lower Helderberg group. Clarksville, N.Y. 40 Lichas Shaly limestone Lower Helderberg group. Clarksville, N.Y. 41 Orthis varica, Conrad. Shaly limestone (26) Lower Helderberg group. Clarksville, N.Y. 42 Strophodonta leavenworthiana, Hall. Shaly limestone Lower Helderberg group. Indian Ladder, N.Y.