Orthoceras was a horn like cephalopod that’s flourished 500 Million Years ago, going extinct 200 million years ago! Related to the squid and octopus family! 
These pieces are about 2 to 2.5 inches length,  about 1inch wide ; and 1/4 inch thick. 
This listing is for 1 Orthoceras Fossil.

Small Orthoceras Fossil