(562 CRUSTACEA. 



Plate 44, fig. 4 a, animal enlarged; l>, head, upper view; c, caudal 

 extremity. 



Sooloo Archipelago. Collected, February 2, 1842. 



Length, five lines. Colourless. There appears to be a small pair 

 of legs near the mouth, then six pairs subequal, the first and last a 

 little smaller than the others, then a mere tubercle or process corre- 

 sponding to a posterior pair. The branches are not jointed, and this 

 is the only reason for thinking the animal immature; the large 

 size of the individual, five lines, seems to show that it is mature, 

 unless it may prove to be young of some Macroural Crustacean. 

 The palpus of the two posterior pairs was a little longer than the 

 other branch, but of the other pairs about the same in length as this 

 branch. The beak is about half as long as the eyes. The abdominal 

 appendages are all imperfect. The last segment has a longish spinule 

 at either angle of apax, and several quite short and equal between 

 these. The caudal lamellae are about as long as the caudal segment, 

 and are furnished with setae. The outer is not jointed. 



The antennae were mutilated. The inner pair was provided with 

 two short setaceous branches. 



SUBFAMILY II. SCELETININ/E. 



The only species of this group observed have the front of the cara- 

 pax deeply tridentate, the middle acute process being a long beak. 



GENUS SCELETINA, Dana. 



Carapax ovatus, anticb transversim constrictus insiar colli, et fronte 

 tricuspidatus. Abdomen tenuissimum. Oculi longi, obconici. &g- 

 mentum abdominis posticum truncatum et spinulis incequis armatum. 

 Pedes thoracici elongati duodecim, biramei, ramo pediformi 4-5-ar<i- 

 culato, altero (palpo) setis panels instructo. Pedes alii quatuor antici 

 parvuli. Appendices abdominis rudlmentarii. 



Carapax ovate, with a constriction across anteriorly like a neck, tri- 



