100 MESSRS. NOEMAN AND STEBBING ON THE 



ments, except that the central (fourth) peraeon-segment, which carries the shortest pair 

 of legs, is also a little narrower than that which follows it. 



The first five segments of the pleon are short, produced on either side into long 

 narrow processes pointing backwards and downwards (i. l), so as not to be seen from 

 above ; the sixth segment (i. ur) widens a little from the base, not far from which the 

 caudal appendages are inserted ; beyond their insertion it is narrowed, and a small 

 globose portion ends in a produced apex ; the whole length of the segment nearly 

 equals that of all the five which precede it ; beneath it has a nearly circular opening 

 with two opercular valves opening sideways, as in the genus Apseudes. 



The upper antennas (i. act) have the basal joint about two thirds the length of the 

 cephalic plate, rather stout, carrying two rows of divergent cilia ; the second joint is of 

 less breadth and short; the third still narrower and very short. The flagellum has 

 seven articulations, some of which carry fine, glass-like, two- or three-jointed olfactory 

 appendages ; the secondary filament has three articulations. 



The lower antennas have the basal joints something like the ophthalmic processes in 

 size and shape ; the three following joints are short, the fifth as long as the four which 

 precede it taken together; the flagellum has four slender articulations, and slightly 

 exceeds in length the last joint of the peduncle. 



The first gnathopods (i. gn l ) have the basos bulky, with a small spine on the hinder 

 margin, the ischium wanting, the meros small, the wrist large, irregularly oblong, but 

 very narrow at its articulation with the meros. The great hand is set on at right 

 angles to the wrist, like the head of a hatchet or hammer; it has a narrow oblong 

 elongated thumb, so curved backwards at the base as if it were out of joint, and into 

 the cavity thus formed a blunt tooth projects from the inner side of the finger; the 

 thumb is distally truncate, with its horny unguis set nearest to the external margin. 

 A similar unguis on the finger closes down within this. 



The second gnathopods (i. pi 2 ) are very like the corresponding limbs in Apseudes ; 

 the basos is bulky and twice as long as broad, the ischium so short as to be almost 

 linear; the meros much shorter than the wrist, carrying one distal spine on the front 

 margin ; wrist long and narrow, ciliated on the back, and having a row of spines (four) 

 with intervening solitary setse in front ; these spines gradually increase in size distally : 

 the hand is about two thirds the length of the wrist, and, like it, is ciliated on the 

 back, where it also has two small distal spines ; in front is a graduated row of about 

 four spines ; the finger is furnished with one or two small denticles on its inner margin. 

 In the specimen described one of the gnathopods of this pair had five spines in the row 

 on the wrist and three on the hand, while the other had four on each of the joints. 



In the first peraeopods {i.prp 1 ) the basos has a small spur near the base of the front 

 margin and a large spur near the distal end of the dorsal margin ; the ischium is very 

 minute, the meros and carpus are equal in length, ciliated on both margins, with one or 

 two stumpy spines on the front ; the hand is large, flat, narrow, slightly curved, with 



