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U.S. NATIONAL MUSEUM BULLETIN 271 



Figure 3. — Lysiannassidae : a, antenna 1, note very short peduncle [see Sebidae]; h, gnatho- 

 pod 2, and an extreme variation of articles 6-7, as offset; note elongation of article 3 

 [highly characteristic overall shape, but see Sebidae, Stegocephalidae]. 

 Stegocephalidae always lack molars and palps on mandibles, have some foliaceous portions 

 on maxillae, always have a 1-2-articulate accessory ilagellum and a characteristic shape of 

 coxae 1-4. The combination of those characters never occurs in Lysianassidae. 



