1156 CRUSTACEA. 



quarto lato, subovato, apice spiniformi. Pes posticus maris dexter vix 

 crassus; manu angustd, breviusculd, digito rnobili vix longhre, acumi- 

 nate, digito immobili setiformi, longissimo, reflexo. Styli caudales 

 elongati, setis mediocribus. \Abdomen 5-articulatum.'] 



Front rounded. Cephalothorax six-jointed, posterior angles long 

 acute and remote, head separate, posterior segments three. Inferior 

 eyes large and very much elongate. Anterior antennae much 

 shorter than the body, divergent 100° to 110°, the left below middle 

 very slightly bent, and beyond abruptly more slender, twenty-one- 

 or twenty-two-jointed ; setae short. Right antenna of male nine- to 

 ten-jointed, the fourth joint broad subovate, the apex a stout spine, 

 the following joints slender. Right leg of posterior pair in male 

 hardly stout, hand narrow, shortish, moveable finger acuminate, 

 hardly longer than hand, immoveable finger setiform, very long, 

 reflexed. Caudal stylets elongate, setae of moderate length. [Ab- 

 domen five-articulate, joints short, subequal, the third having a, 

 process on the right side.] 



Plate 81, fig. 2 a, animal, enlarged (the posterior antennae omitted); 

 2 5, one of the six posterior natatories ; 2 c, right foot of genital pair ; 

 2 d, left foot, ditto. 



Collected in the Atlantic, 4 A. m., November 3, 1838, latitude 0° 40' 

 south, longitude 18° west; perhaps the same, latitude 7° 25' north, 

 longitude 20° west, October 17, 1838. 



Length, one-twelfth of an inch. Colour, blue, with a broad yellow- 

 ish band across the cephalothorax; middle portion of the extremity of 

 the antennae, red. The inferior eyes are much prolonged, and in a 

 vertical view, the pigment extends forward to the front. The poste- 

 rior acute angles of the cephalothorax are much prolonged, and the 

 right, in the male specimen examined, was nearly as long as the 

 abdomen. The caudal stylets are rather longer than half the abdo- 

 men ; and the margin from which the setae proceed extends from the 

 middle of the outer side to the inner apex. The inner seta is but 

 slightly shorter than the second. The left anterior antenna has a 

 seta to the eleventh joint from the extremity, a little longer than 

 others near. The right has the first joint short; the second much 



