1120 CRUSTACEA. 



Slender. Front triangular. Cephalo thorax obtuse behind, five- 

 jointed, head separate, unarmed. Anterior antennae widely divari- 

 cate, nearly straight, scarcely as long as the body, seven- or eight- 

 jointed, last three joints short, three preceding much elongate and 

 subequal; setae long, anterior penult short, posterior penult twice 

 longer, and half shorter than apical. Caudal stylets oblong, slender, 

 setae spreading. 



Plate 79, fig. 2 a, animal, enlarged j h, one of the posterior thoracic 

 legs. 



Collected several individuals off Patagonia, January 14 and 15, 

 1839, latitude 3H°-32° south, longitude 48*°-49£° west. 



Colourless and limpid, a little purplish along the venter. The 

 three posterior segments of the cephalothorax are about one-third the 

 length of the whole ; the last longest. The posterior feet or appen- 

 dages to this last segment are very short, and bear two setae; one quite 

 long and a little curved, the other less than a fourth as long. The 

 inferior eyes have a light red pigment. The superior are either con- 

 nate or approximate ; it was difficult to see them, on account of the 

 pigment of the inferior eyes directly below, on which they were pro- 

 jected in an upper view. The anterior antennae have seven distinct 

 joints, with an appearance of another near the base. The setae are 

 mostly a third the length of the organ. The last three joints are 

 together hardly longer than the one next preceding, and they may be 

 viewed as forming a single joint : there are two long setae at apex, 

 directed forward and outward, and two others directed straight back- 

 ward 5 and one long seta proceeds from the posterior apex of the fourth 

 joint from the apex. The long joints of the antennae are indistinctly 

 subdivided. The caudal stylets are longer than twice their diameter: 

 the setae are about as long as the abdomen. The abdomen is three- 

 jointed ; but the first segment is sometimes very short, or is quite con- 

 cealed. Of the four pairs of natatories, the first and last are a little 

 shorter than the others. There were two oval glands in the thorax, 

 within the penult joint, and partly in the preceding, corresponding to 

 the blue glands in the Pontellae; they are probably ovarian. 



