MARINE. GAMMARIDEAN AMPHIPODA 285 



opsids. Oedicerotids have an elongate peduncle of uropod 3, equal 

 rami of uropods 1-2, unnotched upper lips, strongly setose appendages 

 and disproportionately long fifth pereopods. 



Stilipedidae have a broad, pardaliscid mandibular incisor, no molar 

 and foliaceous maxillae. 



Isaeids and their relatives have strongly triturative mandibular 

 molars and usually have subchelate and/or large gnathopods. 



Key to the Genera of Laphystiopsidae 



1. A large rostrum present (fig. Ilia) 2 



Rostrum absent (fig. Ill/) Prolaphystius 



2. Palp of maxilla 1 biarticulate (fig. 111m) Prolaphystiopsis 



Palp of maxilla 1 uniarticulate (fig. llle) Laphystiopsis 



Genera of Laphystiopsidae 



Laphystiopsis Sars 



Laphystiopsis Sars, 1895. — Stebbing, 1906. 



Type-species: L. planifrons Sars, 1895 (monotypy). 



Rostrum well developed ; mandibular molar conical, unridged ; palp 

 of maxilla 1 uniarticulate; telson short, oval; pleonite 3 not forming a 

 projecting shelf; coxae not touching serially. Species: 3, boreal to 

 China Sea, littoral to bathyal (900 m). 



Prolaphystiopsis Schellenberg 



Prolaphystiopsis Schellenberg, 1931. 



Type-species: P. platyceras Schellenberg, 1931 (monotypy). 



Rostrum well developed; mandibular molar truncate, poorly ridged; 

 palp of maxilla 1 biarticulate; telson short, oval; pleonite 3 not 

 forming a projecting shelf; coxae not touching serially. Species: 1, 

 subantarctic, littoral. 



Prolaphystius K. H. Barnard 



Prolaphystius K. H. Barnard, 1930. 



Type-species: P. isopodops K. H. Barnard, 1930 (monotypy). 



Rostrum absent; mandibular molar truncate, poorly ridged; palp 

 of maxilla 1 biarticulate; telson long, linguiform; pleonite 3 forming a 

 shelf-like projection ; coxae of medium size, touching serially. Species: 

 1, antarctic, bathyal (406 m). 



