REPORT ON THE AMPHIPODA. 681 



the tliird pair shorter than the rami, rami lanceolate, with few spines, the inner finely 

 pointed, not reaching to the nail of the outer, both bordered within with plumose seta3. 



Telson extending fully as far back as the peduncles of the third uropods, cleft for 

 three-quarters of its length, narrowed distally, a spine above and another below the middle 

 of each outer margin, and one in each apex ; all these with accessory threads. 



Length, without the antennse, two-fifths of an inch. 



Locality. — Kerguelen Island. The particular place or depth was not recorded in 

 regard to the specimen figured and described. A second specimen was taken at the 

 surface in Betsy Cove, and a third at Station 149h, oft" Cumberland Bay; depth, 

 127 fathoms ; bottom, volcanic mud. 



Remarks. — The specific name refers to the cavity in the palm of the second gnathojiods. 

 In the course of the description the differences have been noticed between this and the 

 very similar species, OrcJiomene musculosus, taken at an enormously distant station to 

 the south of Japan. The present species agrees better with Boeck's definition of 

 OrcJiomene in so far as the inner plate of the first maxilte is elongate, but agrees worse 

 with it, in so far as the large outer plates of the maxillipeds, though perhaps extending 

 as far as the second joint of the palp, cannot be said, in accordance with the definition, 

 to extend beyond it. Boeck himself does not seem to have laid much stress on the latter 

 point, since, in describing Orchomeyie serratus, the type species, he says that the outer 

 plates of the maxillipeds reach about to the end of the second joint of the palp. 



Genus Lysianax, altered from Lysianassa, preoccupied. 

 LysiaiMssa, Milne-Edwards, 1830. 



For the original definition, see Note on Milne-Edwards, 1830 (p. 141). Boeck, in 

 1872, thus defines this genus, which, since its first institution, has been much 

 subdivided : — 



" Mandibulse mala in margine anteriore dente parvo, sed longo, tenui instructa ; ^Dalpo 

 elongato, in eadem altitudine ac tuberculo molari minuto afiixo. 



" Maxillae Imi paris lamina interna permagna, in apice setam jiarvam aut obsoletam 

 gerenti. 



"Maxillae 2di paris lamina iuteriore lata, exteriore angusta. 



" Pedes maxillares lamina exteriore ovata vixqve in margine interiore nodulosa, uou 

 ad finem articuli 2di palpi elongati augustiqve porrecta ; lamina interiore elongata. 



" Antennae superiores articulo pedunculi 2do et 3tio paulo elongatis. 



" Pedes Imi paris manu non subcheliformi ; articulo 5to elongato, apicem versus 

 attenuato ; ungve parvo. 



" Pedes saltatorii elongati ; ramis paris ultimi brevioribus qvam pedunculo, setosis. 



(ZOOL. CHALL. EXP. PAKT LXVII. 1887.) XxX 86 



