Echinobothrium bonasum sp. n., a new cestode from the cownose ray, rhinoptera bonasus (Mitchill 1815), in the western North Atlantic.

Echinobothrium bonasum sp. n. is described from the cownose ray, Rhinoptera bonasus (Mitchill), taken in Atlantic coastal waters of Chesapeake Bay, Virginia, and off Sakonnet Point, Rhode Island. This species can be distinguished from all others by the following combination of characters: 14 hooklets armature of 11 large hooks, six in the anterior row and five in the posterior row, flanked by 12 to 14 hooklets per side; 24 to 25 spines per row on the cephalic peduncle; 24 to 31 testes per segment, and, wide vitelline bands that overlap the testicular field.