CYCLOPOIDEA. 1255 



culo brevi. Lamellce caudales suborbiculatce, apice inteimo producto, 

 acuto, setis dimicUo lamellce vix longioribus. Maris : — Corpus ovatum, 

 10-articidatum, articidatwne prima, fere obsoleid, segmento postico tecto, 

 quatuor penultimis latere ad angulos posticos acutis. Conspicilla 

 remotiuscula, f route insita. 



Finger of posterior antennae slender, not shorter than second joint, 

 claw short. Caudal lamellae suborbicular, breadth but little less 

 than length, inner apex most prominent, acute, setae hardly longer 

 than half the lamellae. Male: — Body ovate, length nearly twice 

 the breadth, flat, ten-jointed, the tenth concealed, first semicircular, 

 posterior four laterally acute, first articulation nearly obsolete. 

 Conspicilla on the front, a little remote. 



Plate 88, fig. 4 a, male, enlarged ; b, third pair of natatories ; c, 

 fourth pair of natatories ; d, anterior part, showing the relative position 

 and forms of the antennae (a 1 , a 2 ) and (b), the mouth organs and first 

 pair of legs in natural position; e, mouth organs, with one of the legs 

 removed ; /, same, both legs removed ; g, same, one of outer maxillae 

 removed ; h, same, both of outer and one of inner maxillae, removed ; 

 i, one of inner maxillae and mandible ; Jc, I, outer maxilla, in different 

 positions. 



Atlantic, latitude l°-0° north, longitude 17°-18° west, November 

 1 and 2, 1838, specimen figured in figs. 4 a, b, c; latitude 4° 30' south, 

 longitude 25° west, specimens affording figures d to Z, on May 13, 1842. 



Length, one-eighth of an inch. Colours brilliantly opaline, tints vary- 

 ing with the position of the animal; bluish, reddish, purple, yellow, 

 and milk-white are the most common. 



Setae of the anterior antennae about as long as the joints. The 

 finger of the posterior antennae has the first joint about half as long as 

 the second. Claw of posterior antennae not half as long as preceding 

 joint. The inner margin of the stylets is very nearly straight. 



Swims with a very graceful waving motion, turning over and over. 



Sapphirina versicolor. 

 Digitus antennarum posticarum tenuis, articulo 2do vix longior, ungui- 



