432 U.S. NATIONAL MUSEUM BULLETIN 271 



Prophliantidae, revised 



Figures 157, 158 



Diagnosis. — Accessory flagellum absent; body laterally compressea; 

 mandible lacking palp, molar smooth or evanescent; gnathopods 

 feeble but clearly subchelate; telson deeply cleft; uropod 3 biramoug; 

 all of urosomal segments coalesced; antennae very short, not longer 

 than head. See Phliantidae, Eophliantidae, Dexaminidae, Atylidae, 

 Colomastigidae, Kuriidae. 



Description. — Body laterally compressed, urosomites 1-3 coa- 

 lesced; mandible lacking palp, molar smooth or evanescent; lower 

 lip with inner lobes; palp of maxilla 1 uniarticulate; maxilla 2 normal; 

 maxillipedal inner plates small, outer greatly elongate; gnathopods 

 feeble, subchelate; coxae of medium size or large (coxa 5); antennae 

 very short, not longer than head, antenna 2 in type-genus lacking 

 flagellum, in second genus bearing flagellum; uropod 3 biramous; 

 telson deeply cleft. 



Kelationship. — The Eophliantidae have cylindrical bodies and 

 reduced coxae and the gnathopods are simple or parachelate, not 

 subchelate. 



The Talitroidea have distinct urosomal segments and a well- 

 developed mandibular molar. 



The Phliantidae have uniramous or aramous third uropods. The 

 genus Ceina in that family forms a bridge to the Prophliantidae. 



The Kuriidae have a flagellum on antenna 2 and a uniramous 

 third uropod. 



The Atylidae have a mandibular palp. 



The Dexaminidae (including Anatylidae) have only urosomites 2 

 and 3 fused. 



The Prophliantidae are characterized especially by coalesced uro- 

 somal segments, biramous third uropods, lack of mandibular palps, 

 and cleft telsons. 



Haustoriopsis Schellenberg, 1938, is removed from the Haustoriidae 

 to this family. It resembles the type-genus in all respects except that 

 it bears a 3-articidate antennal flagellum whereas Prophlias lacks a 

 flagellum. The coalesced urosomal segments, large coxa 5, similar 

 maxilliped with small inner plates and elongate outer plates, 1- 

 articulate first maxillary palp, absence of mandibular palp, smooth 

 and bulging mandibidar molar, all point to the close relationship of 

 these two genera. Ruffo (1959) suggested that Haustoriopsis be re- 

 moved to the Dexaminidae but I believe that the Prophliantidae 

 should be segregated from that family on the distinctive urosome. 

 Presumably Prophliantidae have been derived from dexaminid-like 

 ancestors. 



