CYCLOPOIDEA. 2065 



articuli secundi subelongatd, articull antepemdtimi posticd longiore 

 (=4 artic.) , penultimis posticd et anticd paulo brevioribus, apicali 

 posticd 7ni?iore, articulo longiore, duabus aliis apicalibus brevibus et 

 subuncinatis. Styli muddles breves; setis mediocribus, pared diffusis. 



Front obtuse. Cephalothorax rounded behind. Anterior antennae 

 straight from the base, and the two lying in the same line, longer 

 than the body, first joint stout and oblong, apical a little bent back, 

 setae short, on basal joint very short, on second joint, a long seta, as 

 long as four diameters of joint ; posterior seta of antepenult joint 

 longest, as long as last four joints, posterior and anterior of penult 

 a little shorter, posterior apical still shorter, longer than joint, two 

 other apical very short and subuncinate or curved. Caudal stylets 

 short, setae little spreading, hardly as long as abdomen. 



Plate 73, fig. 5 a, view, enlarged ; b, extremity of antenna. 



Collected in the Sooloo Sea, southwest of Mindanao, February 1, 

 1842. 



Length, one-twelfth of an inch. Colour, orange, with some red 

 blotches about the mouth and in the thorax. The body is rather 

 slender, and is broadest posteriorly near the first articulation. The 

 inner three caudal setae of each stylet are nearly equal. The antennae 

 have a stout basal joint, which is placed a little oblique to the body; 

 but beyond this the organ extends straight out, with scarcely any 

 curve, so that both are in the same straight line. Last three joints 

 of antennae subequal, the apical a little the longest. The longish seta 

 from the second joint of these antennae, and the two setae on either 

 side of the cephalothorax posteriorly, are striking characters. The 

 abdomen in the specimens was four-jointed. 



b. Cephalothorax 5-6-aeticulatits. 



1, Cephalothorax postice obtusus aut breviter subacutus. 



Calanus SETULIGERUS. 



Frons rotundatus. Cephalothorax 5 (Q1)-articulatus, posticd obtusus, 

 segmentis 4 posticis subcequis. Antennas aniicce corpore paulo longiores, 



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