GAMMARIDEA. 941 



Among the roots of floating Fucus (Macrocystis), at sea, thirty 

 miles southwest of Valparaiso. 



Length, three lines. Colour, greenish. The animal had generally 

 its abdomen curved beneath and the dorsal line of thorax nearly 

 straight (as in the figure). The eyes are round, and the circumfe- 

 rential row contains about twenty lenses. The anterior thoracic seg- 

 ments shortest. Abdomen seven joints, the third longest. Terminal 

 stylets short, extending back beyond second pair, and the second pair 

 slightly beyond the first. Third joint of superior antennae very 

 short and almost like one of the joints of the flagellum. First joint 

 of third and fourth pairs of legs very broad; the next joint is articu- 

 lated with the posterior apex of this joint, and the inner apex is pro- 

 minent and rounded. The first joint of the following pairs is broad 

 ovate, being broadest at base. 



We suspect, from the position of the legs and a comparison with 

 other species, that the fifth and sixth legs in the specimen examined 

 were inverted at extremity, the tarsus being reversed ; but the speci- 

 men was lost with the Peacock, and we cannot verify this suspicion. 



Amphithoe brevipes. 



Feminae: — Corpus compressum, epimeris latis, 6tis subquadratis. Oculi 

 rotwidati. Antennae \mce dimidio corporis paulo longiores, articulo 

 primo longiore, Jiagello plus duplo longiore quam basis, fere nudo, setis 

 latitudine articuli vix longioribus; 2dce lmis fere dimidio breviores 

 basi multo longiore quam bo,sis lmarum, articulis tertio quartoque 

 subcequis, flagello multo breviore quam basis, hirsuto. Manus quatuor 

 subasquce, parvulw, subrectangulatos, hirsutw, apice transversa?, digito 

 minuto. Pedes bti Qti Imi sensim increscentes, setis sat brevibus. 

 Pedes tertii quartique subaequi, articulo primo latissimo. 



Maris : — Manus secunda valida subovaia, supra arcuata, infra (palma) 

 rectiuscula setis paucis brevibus, prope apicem internum dentem mi- 

 nutum gerens, digito longo. 



Female: — Body compressed, epimerals broad, the fifth pair subquad- 

 rate. Eyes round. Superior antennae about half as long as body, 

 first joint longest, flagellum more than twice as long as base, nearly 



236 



