hectarthropidæ

from The Century Dictionary.

• A family of caridean macrurous crustaceans having all of the trunk-legs similar in structure, simple, six-jointed, with the fifth joint not subdivided, and with the first five pairs carrying exopods. It includes the genera Procletes, Icotopus, Eretmocaris, and Hectarthropus, the last being the type.