What is "eschrichtiidae"

Eschrichtiidae or the gray whales is a family of baleen whale (suborder Mysticeti) with a single extant species, the gray whale (Eschrichtius robustus). The family, however, also includes three described fossil genera: Archaeschrichtius and Eschrichtioides from the Miocene and Pliocene of Italy respectively, and Gricetoides from the Pliocene of North Carolina. The names of the extant genus and the family honours Danish zoologist Daniel Eschricht.