AMPHlPOD GENUS LEPTOCHEIRUS. 583 



shorter than 4th, with two chisters of spines on either side ; 

 6th about as long as the 4th, but much more slender, spinose, 

 with groups of spines on either side and 1 very long stout spine 

 inset behind the finger. Finger short, not half the length of the 

 preceding joint, much curved, with 2 specialised bristles towards 

 the apex, one on the inner side lying flat against the finger and 

 reaching to the apex, and the other on the outer side, setting out 

 at right angles to the finger. This one appears to have a flattened 

 tip, and the inner one to be feathered, but the detail is almost 

 impossible to see owing to their extreme tenuity and the angle 

 at which they are placed. Perfeopod 4 is noticeable for the great 

 length of the spines of the 5th and 6th joints ; 2nd joint rounded 

 oval, produced behind into a rounded lobe, 8 spines along the 

 anterior margin, the distal 5 accompanied by increasing clusters 

 of ciliated hairs and setae ; posterior margin with 1 crenulations, 

 and a submarginal row around the lobe of 5-8 ciliated hairs ; 4th 

 and 5th joints practically subequal to each other in length, 5th 

 narrower than 4th ; 6th considerably longer and more slender ; 

 the spines on this joint are longer than those on the 5th, 4 clusters 

 increasing in length and number, on either side, 2 of the clusters 

 behind the finger equalling the joint itself in length ; they are 

 veiy brittle, several of the specimens not having a single perfect 

 one remaining. Finger lightly curved, of the same structure as 

 the finger of the preceding pera3opod. Perseopod 5 : 2nd joint 

 narrow proximally, widened distally ; the proximal end of the 

 posterior expansion is produced subacutely, the distal end, as in 

 peraeopods 3 and 4, forms a rounded lobe ; on the posterior 

 margin are 8 crenulations with a setule on each, and 20 ciliated 

 hairs in a submarginal row ; the anterior margin has 8 spines as 

 in pereeopod 4, and 3 long fine hairs proximally. The 4th-6th 

 joints rapidly increase in length and decrease in width ; 4th and 

 5th each beset with 3 groups of stout spines on either side ; 

 6th twice the length of the 4th, with 5 groups of spines on 

 either side, the terminal posterior group of spines and set?e of 

 extraordinary length. Finger as in perseopod 4. 



The smaller specimens agree in all details with this description, 

 the only difierence being the lesser number of spines. 



Pleopod 1 (fig. 22) : peduncle short, hardly half the length of the 

 outer ramus, with about 10 long plumose setfe on the outer side ; 2 

 small coupling-spines, and 1 long plumose seta inset together on the 

 inner. The outer ramus 12- jointed, considerably shorter than the 

 inner; inner ramus 14-jointed, with 4 cleft spines. Pleopods 2 

 and 3 alike ; peduncle more than half the length of the outer 

 ramus, with only 2 or 3 fine hairs. The rami are shorter than 

 in the 1st pleopod ; outer ramus with 11 joints; inner with 13 ; 



4 cleft spines in the 2Qd pleopod ; 2 in the 3rd. 



Uropods (figs. 23-26) extend backwards to the same level. 

 The peduncle of uropod 1 is shorter than the outer ramus, with 



5 slender spines on the upper curve, and 3 inset diagonally midway 

 on the outer surface ; the falciform apical process reaches to half 



