394 MRS. E. W. SEXTON ON A [Apr. 28, 



4th, five large ones posterioi-ly, five small on the anterior margin, 

 and three large on the anterioi- angle ; the 5th carries one on the 

 posterior margin, two on the anterior-, and two at the distal angle ; 

 and the 6th has two antei'ioi-ly. The distal half of the antei-ioi- 

 margin of the 5th and the whole of the anterior margins of the 

 6th and 7th are dentate. The 7th joint is serrate posteriorly. 



In the young (PI. XXI. fig. 5) the joints are slightly longer 

 than in the preceding pera?opod, but the proportions are the 

 same. 



Fifth Vm^&ovon.— Adult (PI. XXI. fig. 6). The 2nd joint is 

 longer and narrower than that of the in-eceding perajopod, con- 

 cave anterioi-ly, rounded posteriorly and produced downwards in 

 a deep lobe ; the 4th, 5th, and 6th successively shorter and nar- 

 rower, the 4th slightly dilated posteriorly; the 7th small and 

 straight, much shortei- than in the other pereeopods, not quite 

 half the length of the 6th. 



Betce. — The 2nd joint has five minute sensory setules posteriorly 

 so deeply inset as to give a crenulated appearance to the margin. 

 The 2nd and 3i'd joints at their anterior angles each have five 

 large spines. The 4th has nine large strong spines set in deep 

 indentations of the posterior margin, and seven smaller along the 

 anterior margin, with four at the anterior angle — one large and 

 thi'ee small. The 5th carries one small one on the mai'gin, and one 

 at the angle posteriorly ; its anterioi- margin is strongly dentate 

 with five spines inset along the proximal half, the two distal ones 

 being placed together in the same indentation ; at the anterior 

 angle are four spines, one lai-ge and thi'ee small. The 6th has the 

 anterior spinose fringe with two small spines inset ; the anterior 

 angle carries three, and the posterioi- two. The 7th joint is also 

 dentate anteriorly ; the nail minute, not falcate. The hranchicd 

 vesicle attached to this perpeopod is very small. 



In the young (PI. XXI. fig. 7) the 2nd joint is expanded ; the 

 4th, 5th, and 6th are successively longer, not shorter as in the 

 adult ; the 7th is curved, equalling the 6th in length. 



SetcB. — The 2nd joint has one setule on the posterior margin ; the 

 anterior angles of the 2nd, 3rd, and 4th have each one, that of 

 the 5th cari'ies three, while the 6th has one at each angle. 



Pleopoda. — Adult (PI. XXI. fig. 8). The pleopoda are large and 

 powerful. The peduncle is stout, with two little couj)ling-spines 

 on the inner side, of the same construction as those figured for 

 T. nico&ense ; the rami twice the length of the peduncle, and 

 subequal. The outer ramus of the 1st pleopod consists of 21 joints, 

 the first much the largest, carrying six plumose setse on each side 

 in addition to the distal two ; the remaining 20 joints successively 

 decrease in size, each furnished with two long plumose setse. The 

 1st joint of the inner ramus bears on its inner side a tuft of fine 

 hyaline hairs and eight cleft spines ; the seta at the innei- angle 

 of each of the 13 following joints is uncinate. The inner ramus 

 of the 3rd pleopod has seven cleft spines and fifteen uncinate 

 setae. 



