GAMMARIDEA. 333 



flagellum of inferior antenna; d, extremity of leg of first pair; e, ibid, 

 of second pair; /, ibid, of seventh pair. 



Length, five to six lines. The antennae look naked. The superior 

 antennae hardly reach to apex of penult joint of base of inferior an- 

 tennae; last joint of base of inferior antennae a little longer than pre- 

 ceding, and whole base but slightly longer than head and first thoracic 

 segment ; the joints of the flagellum of this pair are longer than twice 

 their breadth. The hand of the first pair of legs is naked below; the 

 preceding joint is very narrow triangular, being widest at apex, and 

 from this part narrowing backward, at first rather rapidly. The third 

 joint of the legs of the second pair is nearly rectangular at lower 

 apex, but obtuse. There are setules on the basal joints of the legs of 

 the last three pairs. The tarsi are very slender and nearly straight, 

 and have a seta below near apex. 



Genus ALLORCHESTES, Daim. 



Antennas lmce elongates, basi 2dorum scepissimb longiores. Maxillipedes 

 apice unguiculatl Pedes lmi 2dique subclielati. Styli Stii caudales 

 brevissimi, simplicissimi. 



Superior antennae longer than base of inferior. Maxillipeds ungui- 

 culate at apex. Feet of first and second pairs subchelate. Poste- . 

 rior stylets very short and quite simple, as in Orchesda. 



The Allorchestes differ from the Orchestiae, in the claw or stout spini- 

 form joint terminating the outer maxillipeds ; in the longer superior 

 antennae, this pair usually exceeding in length the base of the inferior ; 

 in the fifth epimeral being very short, and never nearly as wide as the 

 fourth ; in the carpus of the second pair of legs being sometimes in 

 males produced downward back of the hand, between -the hand and 

 the anterior extremity of the third joint (while in Orchestia, the third 

 joint is never separated from the hand by a portion of the carpus, and 

 the carpus is always short transverse, and is situated wholly above 

 the third joint) ; in the female hands of the second pair, although 

 smaller than those of the male, never being as rudimentary a hand, 

 the form not rounded at apex, the finger not exceedingly minute and 



