174 U.S. NATIONAL MUSiETJM BULLETIN 271 



19. Accessory flagellum absent or represented by a process on article 3 of 



antenna 1 20 



Accessory flagellum formed of a small articulate scale . . . Calliopiella 



20. Pereopods 1-5 minutely subcheliform Bouvierella 



Pereopods 1-5 simple 21 



21. Male antennae with calceoli Halirages 



Male antennae without calceoli Apherusa 



22. Accessory flagellum present . 23 



Accessory flagellum absent 24 



23. Article 5 of gnathopods elongate, much longer and slightly thicker than 



article 6 (exceptional) Cleippides 



Articles 5 and 6 together elongate and of similar thickness . . . Oradarea 



24. Lower lip with small inner lobes . . some species of Apherusa and Halirages 

 Lower lip lacking inner lobes 25 



25. Outer ramus of uropod 3 half as long as inner ramus . . . Leptamphopus 

 Outer ramus of uropod 3 three fourths or more as long as inner ramus . . 26 



26. Palp of maxilla 1 reduced, not reaching end of outer plate . . Laothoes 

 Palp of maxilla 1 normal, reaching or exceeding outer plate 27 



27. Gnathopod 2 perfectly simple, inner plate of maxilla 1 without setae, palp 



of maxilliped not as long as outer plate and its parent article combined. 



Prolaphystius (Laphystiopsidae) 



Gnathopod 2 subchelate, inner plate of maxilla 1 setose, palp of maxilliped 



nearly twice as long as article and its lobe of outer plate 28 



28. Body dorsally smooth Bouvierella 



Body dorsally processiferous some species of Halirages 



Genera of Calliopiidae 



Amphithopsis Boeck 



Amphithopsis Boeck, 1861. — -Stebbing, 1906. 



Type-species: A. longicaudata Boeck, 1861 (selected by Boeck, 

 1876). See Sars, 1895. 



Antennae equal in length; accessory flagellum as long as article 1 

 of primary flagellum; lower lip without inner lobes; gnathopodal 

 palms distinct, article 5 slightly longer than article 6, articles together 

 not elongate, article 5 of gnathopod 1 with slight posterior lobe; telson 

 rounded apically, outer ramus of uropod 3 less than half as long as 

 inner, body moderately depressed. Species: 1, subarctic Atlantic 

 (40-1,505 m). 



Apherusa Walker 



Gossea Bate and Westwood, 1863 (homonym, Coelenterata) . 

 Apherusa Walker, 1891b.— Stebbing, 1906. 



not Phaedra Bate, 1858b (possibly type-species a composite of two specimens, 

 head and body). 



Type-species: Amphitho e jurinei MUne^dwSiTds, 1830 (monotypy 

 and subsequent synonomy). See Sars, 1895. 



