Sessile-cf/rd Crustarenrift. 329 



carapace, that is, the head uitli tlic first pera^oii-sc2jinent, xa 

 nearly twice, as h)ng-as the greatest breadth ; the front ])art is 

 narrowed. The first free scgriieiit of the percec)n is shorter 

 than tlie rest, the next four being subcjuid, and the hast only 

 a little longer than the first. The tlfrii segment of the pleon 

 is rather longer than any of the ])receding four. Tlic last 

 segment is rather longer than the fourth and fifth together, 

 anil is obtusely rounded at the slightly narrowed extremity. 



No eyes are i)ereeptible. 'J'lie upper anfeniue (of the 

 female) are sliorter than the carapace ; tlie lirst ji)int much 

 longer than the next two together, the third a little longer 

 than the second, the fourth quite rudimentary. The lower 

 antenna? are inuch smaller than and implanted considerably 

 behind the upjjcr [)air : the antepenultimate joint is much the 

 longest and curved in lateral view. 



The u[)per lip is dome-sha])ed. The mandibles have a 

 finely serrate cutting-edge combined with a couple of teeth, 

 which are stronger on the left than on the right mandible. 

 The latter is shown in the figure interlocked between the two 

 teeth of the left mandible. As they are seen from below the 

 right mandible is on the left hand. 



The first maxilla consists of a long narrow lobe, curved at 

 the extremity, where it carries fiv^e setai, with a setule on the 

 outer margin a liitle below the apex; the exopod was not 

 observed, but was doubtless of the usual form. 



The niaxillipeds have four strong set« on the terminal joint 

 and two smaller ones on the inner margin of the long penul- 

 timate joint. The central plate appeared to be undivided, but 

 was not clearly observed. 



The first gnathopods have the first free joint massive, 

 larger tlian any of the others, widest near the base, as wide as 

 long ; the second joint is absent or coalesced ; the third is 

 small and triangular, carrying a single setule ; the wrist is 

 more than once and a half as long as broad ; the hand proxi- 

 mally is fully as broad as the wrist, the outer margin very 

 convex, its apex projecting much beyond the base of the 

 finger, and there set with several tubercles ; on the inner side 

 it makes an abrupt bend at a very short distance from the 

 wrist, forming a broad thumb ending in a nail-like process, 

 and carrying two setai on the inner margin and three or four 

 together with some flattened tubercles on the border facing 

 the finger. The finger is irregularly tubereled on the outer 

 margin and smooth on the inner, its tip closing within the 

 unguicular process of the hand. 



The second gnatliopods have the first free joint long, 

 slender, and bent ; the third, fourth, and fifth joints are sub- 

 Aiin.d; Mag. A'. Hist. Ser. 6. Vol. viii. 22 



