CYCLOPOIDEA. 



1199 



Pacific, near the Kermadec Islands, and north towards Tongatabu; 

 abundant ; April 14 to 20, 1840. 



Length, one-twenty-fourth of an inch. Colour bluish, with the 

 whole alimentary cavity deep red. Head very narrow, pointed in front, 

 in upper view. Anterior antennae two-thirds the length of the body, 

 and extremely slender, much more so than in the following species ; 

 the third joint (or second, the first being obsolete) is the longest, and 

 has two curved setae on the outer margin near its middle ; the appen- 

 dage to the fourth joint, with the setae which terminate it, lies nearly 

 parallel with the terminal portion of the antenna, and is two-thirds as 

 long as this portion; this terminal part is four-jointed, the second 

 joint longest, and the last, which is longer than the preceding, has 

 two curved hairs on the posterior margin near middle, and also one or 

 two straight hairs at apex. The second pair of antennae terminate in 

 three moveable setae, but little longer than the last joint. In the first 

 pair of feet, the second joint has its basal portion on the inner margin 

 furnished with a few short setae. 



The outer pair of appendages to abdomen consist each of an oblong 

 joint, having a long curved seta at apex, spinulose externally, besides 

 two or three short setae or spines ; the inner pair appeared to be three- 

 jointed, and had one or two long straight setae at apex, and two 

 unequal and much shorter on the inner margin. The longer setae 

 extend to the last articulation of the abdomen. The external ovarian 

 sac, which has a brownish colour, lies between these two pairs of 

 organs. 



These animals have a very flexible body, and move through the 

 water with a steady, rapid motion. 



Setella crassicornis. 



Maris (?): — Antennae anticce crassiores, rectce, inter sese 130° divaricates ; 

 articulo primo obsoleto, secundo tertioque brevibus, quarto appendiculato, 

 hoc etiam sexto ultimoque tertium longitudine duplo super antibus. 

 Digitus pedis antici dimidii articuli secundi longitudine setae, caudales 

 prope sesqui corporis longitudine. 



MaleiJ) : — Anterior antennae stouter than in the other species; quite 

 straight, angle of mutual divergence 130°, first joint obsolete, second 



