242 Southern Cross. 



DesGriptio7i of Male. 



Body of nearly uniform diameter. The cephalon is broad, roughly 

 quadrangular, the postero-lateral margins being somewhat rounded. 

 The frontal margin bears a broad triangular rostrum in the middle 

 line ; it then becomes straight for a short distance on each side the 

 rostrum, and then incurved, to terminate with a stout pre-ocular spine. 

 Eyes small. The anterior portion of the thorax is separated from the 

 posterior by a conspicuous constriction. Of the three posterior seg- 

 ments, the first is marked in tlie middle line with an ill-defined rect- 

 angular patch, the second bears a median longitudinal groove, and the 

 third is very strongly curved. The abdomen comprises the normal 

 number of segments, and terminates in an elongate triangular telson. 



Antennae. The first antenna consists of a three-jointed peduncle, 

 the last joint being longer than the other two together, and a four- 

 jointed flagellum. The second has a four-jointed peduncle, the two 

 last being large and sub-equal, and the two proximal ones being 

 much shorter. The flagellum is six-jointed. 



Mandible. The mandibles are scythe-like in general appearance, 

 the amount of curvature at the free end being variable. The inner 

 margin is somewhat sinuous, and the outer drops abruptly a little 

 short of its middle. 



Maxillipede. This consists of a roughly triangular plate attached 

 by its broad base ; the inner margin is straight, the anterior slightly 

 sinuous, and the outer is very oblique. The masticatory lobe is a 

 clavate process bearing two stout knobbed setae, which interlock 

 with those from the opposite side. The palp consists of four 

 rounded segments, tapering from the first, and each bearing some 

 half-dozen long setae on its outer margin. 



Gnathopod. This consists of two segments, the first being a large 

 pyriform plate, the more rounded inner margin bearing long plumose 

 setae. The terminal segment is very small, oval, and bears a few 

 long plumose setae towards the extremity, and a few small setae on 

 the inner margin. 



Pereiopoda. Sub-similar, sub-equal. They present no very 

 obvious peculiarities, save that the inner margin has a number 

 of button-like tubercles distributed along it. 



Descrq^tion of Female. 



The fully tleveloped female possesses an enormously swollen 

 body. The cephalon is comparatively small, obtusely pointed in 



