Mr. J. Lubbock on a new genus of Calanidae. 27 



fifth short and produced backwards in form of a strong plate, as 

 long as the sixth joint, turned outwards, and knobbed at the 

 end and strongly serrated, which forms with the corresponding 

 plate of the fourth joint a most beautiful prehensile apparatus 

 (PI. I. fig. 3, 3 « open, 3 b closed), whose action will be presently 

 described. The sixth joint is as long as the plate of the fifth, 

 narrow at the apex, and gradually increasing in size to the base. 

 The outer margin is straight, the inner rather curved and bear- 

 ing two pairs of hairs ; the 7th, 8th, and 9th are short and 

 broad, their breadth exceeding their length ; the 10th is longer 

 and narrower; the 11th, 12th, and 13th the same length but 

 broader; the 7th, 8th, 9th, 10th, 11th, and 12th with a row of 

 hairs externally. 



Rising at the exterior basal angle of the ninth joint a strong 

 voluntary muscle passes through the 8th, 7th, 6th, and is in- 

 serted into the apex of the fifth joint ; the action of which is to 

 draw back the apex of the fifth joint towards the sixth (fig. 3 b), 

 which throws the seiTated plate forwards and towards the plate 

 of the tenth joint. 



This antenna is coloured and extended in front of the animal, 

 while the right is colourless and doubled down close to the 

 body. 



Second pair of antennte (fig. 2) consist of three joints, the 

 apical rather swollen at the end and bearing a tuft of hairs ; the 

 basal supporting a simple appendage not quite so long as the 

 second joint of the other branch, and also terminated by a tuft 

 of hairs. 



Mandibles (fig. 4). Strong, six-toothed, the two external teeth 

 the largest, and each terminated by a small spine, the sixth 

 longer than the rest and more like a stout spine ; bearing a large 

 palpus, which is provided at its apex with two lobes, nearly equal, 

 and each terminated by a tuft of long, setose hairs. 



Internal maxillipeds (fig. 5) consist of a basal joint bearing 

 two lobes, each with several strong setose hairs ; opposite the 

 lobes is another tuft of longei-, also setose hairs, between which 

 and the lobes is attached an oval plate, deeply notched at the 

 extremity, and likewise bearing setose hairs at the apex. 



Second pair of maxillipeds (fig. 6). A small triangular lobe 

 with a few long setose hairs at the extremity, and a long, simple, 

 six-jointed palpus, also terminated by a tuft of hairs. 



External maxillipeds (fig. 7). Large, bearing many long, 

 stout, slightly curved hairs setose internally, and showing traces 

 of being three- jointed. The extremity of the seven external hairs 

 is curiously crenated. 



Thoracic legs. The first four pair (fig. 8) consist of a two- 

 jointed basal part, where arise a long thrce-jointcd and a shorter 



