6 Dr. T. Scott on some 



form narrow prolongations which extend backward to about 

 the last segment of the abdomen (fig. 11). Abdomen short, 

 about half the length of the cephalothorax, composed of 

 three segments, the first large and equal to tally the combined 

 lengths of the next two, second and third subequal ; caudal 

 rami short and furnished with five short and stout bristles 

 round the distal end. 



Antennules elongated and reaching to about the last 

 segment of the abdomen. The other appendages of the 

 cephalosome and also the swimming-legs are all somewhat 

 similar to the species named above, except that in the fi.th 

 pair of thoracic legs the spiniform process on the inside of 

 the second joint of the outer ramus is larger and reaches 

 beyond the end of the third joint and Las its extremity 

 slightly hooked. 



Length about 1 6 mm. 



Male. — The male, as is usual, is smaller and more slender, 

 and the abdomen proportionally longer than in the female. 

 The fifth pair of thoracic legs differ very much from those of 

 the female, and they are also unsymmetrical ; the inner ramus 

 of the left leg is very rudimentary ; in the outer ramus 

 the first joint is of an oval form and considerably dilated 

 and becoming somewhat gibbose interiorly; the distal portion 

 of the ramus is narrow, strongly curved, and attenuated 

 towards the extremity ; the first joint is also armed with a 

 stout and moderately long spine near the low r er end of the 

 outer margin ; this spine projects outward from the joint, as 

 shown in the figure (fig. 2), and which is apparently its 

 normal position. The outer ramus of the right leg is dis-- 

 tinctly shorter than that of the left, but is scarcely so robust ; 

 the inner ramus is tolerably stout and broad, and reaches to 

 somewhat beyond the end of the first joint of the outer 

 ramus, and is rather wider towards the proximal end, where 

 the iuner margin expands and becomes somewhat gibbose 

 and carries one or two short spines ; the distal end of the 

 inner ramus is bluntly rounded and is provided with two 

 short spiniform setse on the outer distal angle, while on the 

 inner angle and extending a short distance up the inner 

 margin are five or six short and stout hooks, as shown in the 

 figure (tig. 2). Moreover, the articulation of the inner ramus 

 to the basal joint forms a distinct hinge, which permits of the 

 ramus turning inwards so as to interlock with a recess on 

 the inside margin and near the proximal end of the left leg. 

 A spiniform seta springs from the outer distal angle of the 

 basal joint, and a small fork-like appendage may also be 

 observed on its inner aspect (fig. 2). In the structure of the 



