51 337 Strophodonta planulata, Hall. Lower Helderberg group. Cedarville, N.Y. 338 Streptorhynchus woolworthianus, Hall. Lower Heldubus group. Cedarville N.Y. 339 Streptorhynchus woolworthianus, Hall, Shaly Limestone Lower Helderberg group. Clarksville N.Y. 340 Acidaspis hamata, Conrad (segment spines) Shaly limestone Lower Helderberg grp. Clarksville, N.Y. 341 Strophodonta Lower Helderberg group, Clarkville N.Y. 342 Chonetes n.sp. Lower Helderberg group. Cedarville, Herkimer Co. N.Y. 343 Acidaspis lamata, Conrad. Shaly limestone Lower Helderberg group. Clarksville, N.Y. 344 Eurypterus prominens, Hall. Clinton group? Cayuga Co? New York. 345 Streptelasma strictum Hall. Shaly limestone Lower Helderberg group. Clarksville N.Y. 346 Orthos tectostata, Hall. Shaly limestone Lower Helderberg group. Clarksville, N.Y. 347 Orthis perelegans, Hall. Shaly limestone Lower Helderberg group. Clarksville, N.Y. 348 Orthis oblata, Hall. Shaly limestone Lower Helderberg group. Clarksville, N.Y. 349 Orthis subcarinata, Hall. Shaly limestone Lower Helderberg group. Clarksville, N.Y. 350 Merista princeps, Hall. Shaly limestone Lower Helderberg group. Becraft, Mt. Hudson, N.Y.