Abstract
A collection of 1,857 adult cestodes classically called Taenia pisiformis Bloch, 1780: Multiceps multiceps (Leske. 1780); and Hydatigera taeniaeformis Batsch, 1786, from coyotes, feral house cats, and grey foxes were restudied to evaluate traditional characters used in their taxonomy. This work was supplemented by studies of coenuri of Multiceps multiceps from naturally infected jackrabbits, swamp rabbits, and cottontails plus those of experimentally infected laboratory mice. Results of the study reveal that most characters previously employed in separating the species are not valid on the generic level and that the comparative sizes of long and short rostellar hooks provide the most reliable criteria for separating them. Consequently, M. multiceps and H. taeniaeformis are relegated to T. multiceps and T. taeniaeformis, respectively.