6(54 CRUSTACEA. 



segments armed laterally or below with an acute spine, last segment 

 linear, truncate at apex. First antennas a little shorter than 

 thorax, five-jointed, cylindrical, last joint longest. 



Plate 44, fig. 5, animal, enlarged. 



Atlantic, latitude 30' south, longitude 17 30' west. Caught one 

 individual, November 3, 1838. 



Length, one-seventh of an inch. Colourless. At the front angles 

 the carapax is very much broader than at the constriction ; behind 

 the constriction it widens and bears a spine either side, then gradually 

 narrows, and at its posterior extremity is not wider than the slender 

 abdomen. The beak is. rather longer than the eyes. The sixth and 

 seventh abdominal segments are about equal in length. Outer caudal 

 lamella not jointed. Inner antennas simple, cylindrical, only five 

 joints observed, the second and last longest. A few rather long hairs 

 on inner margin. The outer pair has two cylindrical branches or 

 flagella on a short base, of which only one joint was distinguished. 

 The branches were broken at their extremities ; the part remaining 

 consisted of long joints, and not of short ones like the flagella of other 

 genera; first joint of the two branches of about the same length, 

 second of inner branch about half the first joint. 



Posterior legs considerably the shortest. The palpus is cylindrical, 

 few-jointed, and not multiarticulate at extremity. The abdominal leg^ 

 are small and naked. 



SCELETINA LATICEPS. 



Carapax 2ong rostratus, latissimus, parce constrictus, cuspidibus latf- 

 ralibus paululo divaricatis, collo latissimo, humeris nan armatis. Ab- 

 domen tenuissimum ; seymento postremo lineari, apice emarginato. 

 lateribus media spinulam minutam ferentibus. Antennae internee 

 tenues, articulo primo oculis duplo longiore. Pedes postici preceden- 

 tibus dimidio/ere breviores, palpo 2-articulato. 



Carapax long rostrate, very broad anteriorly, sparingly constricted, 

 neck therefore very broad, and anterior angles of carapax but little 



