^290 CRUSTACEA. 



tudine duplo superante. Styli cauddles brevissimi, parum divaricati; 

 seta secundd corpore paulum breviore, tertid fere dimidio minore, reli- 

 quis brevissirnis. 



Female: — Cephalo thorax oblong ovate, segments (in an upper view) 

 acute at tbe posterior angles. Abdomen abruptly narrower than 

 last segment of thorax, broad, six-jointed, sides regularly a straight 

 line and breadth a little diminishing posteriorly, first segment very 

 short. Anterior antennae short, nine-jointed, basal joints four in 

 number, attenuate ; setae short, a little longer at apex, and equalling 

 in length the last five joints together (the flagellum) . First pair of 

 feet small, second joint having an obtuse angle within and the 

 finger hardly half its length. Caudal stylets very short, somewhat 

 divaricate, second seta about three-fourths the length of the body, 

 third nearly one-half shorter, the others minute. 



Plate 83, fig. 7 a, female, enlarged; b, extremity of posterior an- 

 tenna; c, extremity of a maxilliped (?); d, first pair of feet; e, second 

 pair of feet ; /, bag of eggs. 



Found at sea, thirty miles off Valparaiso, on floating sea-weed, May, 

 1839. 



Length, one-twentieth of an inch. Beak small, semicircular. Eyes 

 on a large spot of deep red pigment. First segment of body longer 

 than broad. Abdomen rather broad, and slightly but very irregularly 

 tapering, with straight sides. Stylets scarcely longer than broad. 

 Anterior antennae curve a little forward and then directly outward, 

 so that the two are nearly in the same straight line ; they admit of 

 flexion and even curl up at times ; the third and fourth joints are 

 rather longer than the preceding. First pair of legs have the stout 

 claw-shaped finger applied against the lower part of inner surface of 

 second (or preceding) joint. There is a pair of short appendages to 

 the first abdominal joint. Ovarian sac broad and large, as long as 

 abdomen and light flesh-coloured. 



This species was abundant on the Fucus, over which, while it is 

 wet, it creeps with rapidity, showing great flexibility of body. It 

 swims with a nearly steady motion. It often attached itself to the 



