132 GAMMARTT)^. 



articulates towards the posterior margin of the foot, and 

 is directed backwards^ contrary to the usual plan in the 

 Amphipoda ; it is short, strong, and sharp, and furnished 

 on the outer surface with a few minute hairs. The sixth 

 pair of legs resemble the preceding, except that the se- 

 cond joint is larger. The seventh pair differ from all the 

 preceding: the second joint is very long; the plate is 

 long-ovate, broader below than above, and postero-infe- 

 riorly produced to the extreinity of the next succeeding 

 joint ; the foot is long-ovate, and furnished at the distal 

 extremity with a few hairs and spines ; the finger is 

 broad, flat, straight, and lanceolate : near the posterior 

 margin is a longitudinal row of circular spots. The caudal 

 appendages are unequal in length ; the antepenultimate 

 have the branches longer than the peduncle ; the lower 

 branch is simply styliform, the upper is slightly longer, 

 of the same form, but having the upper margin fringed 

 with a row of equidistant spines. The penultimate pair 

 have the peduncle with the upper margin spinous ; the 

 branches are subfoliaceous, and curved so as to fit one 

 against the other, and both have their margins thickly 

 fringed with eqviidistant sharp spines. The ultimate pair 

 are likewise subfoliaceous : the lower branch has the lower 

 margin fringed with spines, and the distal extremity 

 of the upper is furnished with simple hairs ; the upper 

 branch is broader than the lower, and has the under 

 surface hollowed, to admit of the under branch being 

 closely pressed against it ; it has only the distal in- 

 ferior margin furnished with hairs. The middle tail- 

 piece is longer than the peduncle of the last pair of 

 caudal appendages, narrow, and divided to nearly two- 

 thirds of its length, and the lateral margins are bent 

 to an angle. 



