GAMMARIDEA. 



845 



twice as long as base, very slender ; superior nearly half shorter, 

 flagellum not twice as long as base. Four anterior feet densely 

 hirsute on the inner or anterior side of last two or three joints ; 

 three posterior pairs similar; the seventh much longer than the 

 sixth. 



Plate 5Q, lig. 4 a, animal, enlarged; a', same, natural size; h, abdo- 

 men extended straight; c, outline of part of same, showing dorsal out- 

 line; d, mandible; e, maxilla of first pair; /, ibid, of second pair; g, 

 maxilliped. 



Balabac Passage, north of Borneo; brought up on corallines in 

 thirty-one fathoms. 



Length, two lines. Colour, a little reddish. The head is more 

 than twice as broad as long and is triangular with one angle in front, 

 and the eyes occupying the lateral angles. The fourth segment of the 

 thorax is broadest ; the first and second much shorter than either of 

 the following ; the last longest, and as narrow as the first. The legs 

 are all vergiform and similar, except that the four anterior are hir- 

 sute on the anterior or inner side ; in the second pair, only the last 

 two joints preceding the claw are thus hirsute. The other legs have 

 only a few very minute setae. The eyes are a little oblong, nearly 

 transverse with the head. The superior antennae have the first joint 

 of base largest; the second a little longer than third; the whole organ 

 is a little longer than the thorax. The base of the inferior pair is 

 longer than the base of the superior by its last or fourth joint, which 

 is long and slender, and nearly as long as preceding part of base ; 

 third joint a little longer than half the fourth ; two preceding short. 

 The third and fourth pairs of legs are a little stouter than first or 

 second, though still slender. The first joint of seventh pair is pro- 

 minently acute at posterior apex ; the fifth and sixth pairs are nearly 

 equal. 



The abdomen has an acute triangular process at centre of posterior 

 margin of first three joints. As the abdomen is generally curved up 

 under the body, at about the third articulation, one of these spines 

 projects behind. The three pairs of stylets are rather long, and 

 extend back some distance. The branches of the last pair are quite 

 unequal. The forms of the organs of the mouth are shown in the 



figures. 



212 



