70 



U.S. NATIONAL MUSEUM BULLETIN 271 



Figure 19. — Amphilochidae : a, coxae 1-4, left to right [see Leucothoidae, Pleustidae, 

 Calliopiidae, Stegocephalidae]; b, accessory flagellum absent [see Stegocephalidae]; c, 

 uropod 3, note biramous condition [Stenothoidae, Cressidae, Thaumatelsonidae]; d, 

 telson, entire [with one exception]. 



Stegocephalidae have mandibles always without molars and palps, whereas Amphilochidae 



have mandibles with either one or both occurring together. Anamixidae have a ventral 



cephalic keel replacing mandibles and maxillae. 



