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U.S. NATIONAL MUSEUM BULLETIN 271 



Figure 2L — Leucothoidae : a, mandible, note absence of molar; h, extremes of accessory 

 flagellum, always very small; c, maxilliped, note obsolescence of outer plate; d, gnathopod 

 1, note complex subchelation [see Cressidae, Thaumatelsonidae, and Stenothoidae, all 

 of which also have uniramous uropod 3]; e, telson, entire. 



Sebidae have a uniramous uropod 3 and chelate gnathopod 2. Anamixidae, resembling 



Leucothoidae strongly, lack maxillae and recognizable mandibles, and have a strongly 



reduced coxa I. 



