"Waldheimia flavescens. Interior of dorsal valve. c, c', cardial process; b', hinge-plate; s, dental sockets; l, loop; q, crura; a, a', adductor impressions; c, accessory divaricator; b, peduncle muscles; ss, septum." — Encyclopedia Britanica, 1893

Dorsal Valve

"Waldheimia flavescens. Interior of dorsal valve. c, c', cardial process; b', hinge-plate; s, dental…

"Terebratula virea. Interior of dorsal valve. l, loop; b, hinge-plate; c, cardinal process." — Encyclopedia Britanica, 1893

Dorsal Valve

"Terebratula virea. Interior of dorsal valve. l, loop; b, hinge-plate; c, cardinal process." —…