H12 CRUSTACEA. 



ribus, apicali posticd articuli longitudine, posticd penultimd paulo Ion- 

 giore, anticd penultimd breviore. Antennarum posticarum ramus 

 minor tenuis, valde brevior. Pes posticus dexter mediocris, articulo 

 ultimo subuncinato, appendice laterali subcorned, articulum uncinatum 

 longitudine superante. 



Male : — Cephalothorax five-jointed, there being four posterior seg- 

 ments, posterior angles long acute, right one the longer. Basal 

 part of anterior antennae arcuate, the rest straight, a little shorter 

 than the body, twenty-two or twenty-three-jointed, the second joint 

 a little oblong 5 setae short, a few longer than second joint, poste- 

 rior apical as long as apical joint, posterior penult a little longer, 

 anterior penult shorter. Shorter branch of posterior antennas 

 slender, and about half as long as the other. Right leg of posterior 

 pair of moderate size, last joint subuncinate, lateral appendage sub- 

 corneous, exceeding the uncinate joint in length. 



Plate 78, fig. la, animal, enlarged; b, second pair of antennae; c, 

 palpus of mandible ; d, maxilla ; e, maxilliped ; /, one of the natar 

 tories. 



Atlantic, latitude 7°-9° north, longitude 21° 40'-24° 15' west, Oc- 

 tober 13 and 18, 1838; latitude 6° south, longitude 24° west, Novem- 

 ber 8, 1838. 



The specimens affording the above description, have also the follow- 

 ing characters. Last four segments of cephalothorax about two-fifths of 

 the whole length ; the first articulation less distinct than the follow- 

 ing. Right posterior angle much prolonged and very acute in an 

 upper view. Abdomen four-jointed, last segment shortest. An- 

 tennae a little unlike, the right being slightly incrassate at middle. 

 In many specimens the last eleven joints were black ; in one indi- 

 vidual only seven were black, and in another only five. The poste- 

 rior apical seta is about as long as apical joint; the posterior penult is 

 a little longer and the anterior penult shorter. The posterior antennae 

 have the longer branch broad at base and tapering. Maxillae fur- 

 nished at the posterior apex of penult joint with a pencil of setae 

 half as long as the cephalothorax. Maxillipeds appear to be three- 

 jointed. The first joint nearly twice as long as the second, the third 



