1222 CRUSTACEA. 



crasswm, postich attenuatum, segmento ultimo subcylindrico. Slyli 

 cauddles dimidio abdominis breviores, divaricati, setisparce longioribus. 



Cephalothorax stout, fourth segment much prolonged behind and 

 acute. Conspicilla small, remote. Anterior antennae seven-jointed, 

 setae shorter than the antenna. Abdomen stout, attenuate behind, 

 three-jointed, third segment nearly cylindrical. Caudal stylets 

 shorter than half the abdomen, divaricate, setae a little longer. 



Plate 86, fig. 3 a, animal, enlarged; a', anterior antenna; ft, poste- 

 rior antenna ; c, first pair of feet ; d, one of the natatories of second 

 pair ; e, abdomen, lateral view. 



Atlantic, latitude 3° 45'-4° 20' north, longitude 19° 30'-18° 30' 

 west, October 26, 27, 1838; latitude 6° 20' south, longitude 24° west, 

 November 8, 1838. 



Length, one-twenty-fourth of an inch. Colourless, or but slightly 

 bluish. 



The abdomen is fusiform in shape. The stylets are but little longer 

 than the last segment. The second and fifth joints of the anterior 

 antennae are longer than the others. The finger of the posterior 

 antennae is about or nearly half the length of the second joint. The 

 naked setae are as long as this joint. The natatories of the four pairs 

 have both branches three-jointed. The pigment of the large eyes 

 extends backward into a prominent carinate ridge, on the under side 

 of the cephalothorax, and this ridge has a nearly semicircular outline. 



CORYCiEtTS VENUSTUS. 



Cephalothorax mediocris, segmento quarto breviter acuto. Conspicilla 

 remotiuscula. Antennm anticw elongate setigerae. Antennarum posti- 

 carum articulus 2dus digito fere duplo longior, apice interno denfo- 

 formi, seta longd, nudd, digito subceque 2-artieulato. Abdomen 2-arti- 

 culatum, segmento primo paulo latiore et longiore. Styli caudales 

 abdomine paido breviores, divaricati, setis abdominis longitudine. 



Cephalothorax moderately stout, fourth segment very short acute. 



