English: The prosomatic appendages of Limulus polyphemus (right) and Scorpio (left), Palamnaeus indus compared. The corresponding appendages are marked with the same Roman numeral. The Arabic numerals indicate the segments of the legs. cox, Coxa or basal segment of the leg. stc, The sterno-coxal process or jaw-like up-growth of the coxa. epc, The articulated movable outgrowth of the coxa, called the epi-coxite (present only in III of the scorpion and III, IV and V of Limulus). ex1, The exopodite of the sixth limb of Limulus. a, b, c, d, Movable processes on the same leg. (From Ray Lankester, Quart. Journ. Micr. Sci., vol. xxi., 1881.)
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