1050 



CRUSTACEA. 



flexed backward, as long as the last joint, the anterior remote from 

 the apex, subapical setae minute. Caudal stylets very short, setae 

 unequal, the second longer than abdomen with the apex curved 

 outward, the others a little shorter than the abdomen. 



Plate 72, fig. la, animal, enlarged; a', natural size; b, extremity 

 of anterior antenna, enlarged ; c, side view of body, showing alimen- 

 tary canal {%, i) and position of heart (h) ; d, a young animal, possibly 

 of this species; caught, April 9, 184a, at the same time with the pre- 

 ceding. 



South of Tongatabu, in latitude 32° 24' south, April 9, 1840, when 

 many specimens were caught; also, near Gilbert's Island, April 19, 

 1841; also, latitude 28° north, longitude 171° 30' east, May 17, 1841. 



Length, one line. The body is stouter than usual; the beak is 

 short, and in a side view is not incurved. The unequal setae of the 

 caudal stylets is a prominent characteristic. The setae of the antennae 

 are short; those near the base scarcely longer than the diameter. 

 The terminal joint has some appearance of being double, the setae on 

 the anterior side being at the apex of what might be thought the first 

 of the two joints. The posterior setae of the two subapical joints are 

 nearly obsolete. The anterior seta of the fourth joint, counting from 

 the apex, is a little elongated, and the same is true of that of the 

 seventh joint, both being a little longer than the joint to which 

 attached; while the setae of the other joints in the same part of the 

 antennae are very short. 



The posterior antennae have the anterior branch much the longest. 

 The setae of the following organs are moderately short. Caudal setae 

 spread but little. The abdomen has four joints, of which the first is 

 much the longest. 



Calanus comptus. 



Frons rotundatus. Cejphalothorax i-articulatus, posticd obtusxm. An- 

 tennae anticce tenuissimce, cephalothorace paulo longiores, ferine 2i-artir 

 culatce, duplo curvatce, apicibus fronte posterwribus, articulo ultimo 



