50 THE VOYAGE OF H.M.S. CHALLENGER. 



&st segment of tlie l^ody is considerably swollen at the base of the mandibles, constricted 

 posteriorly, and shows a faint line at the beginning of the first true thoracic segment. 

 The abdomen is comparatively long. The upper surface .of the body is armed with 

 numerous spines, forming in the middle of the segment star-like groups (PI. IV. fig. 12), 

 and scattered more irregularly on the lateral processes ; near the end of these a row 

 of stronger spines is observed. The oculiferous tubercle is, especially in the females, 

 highly elevated, and shows four dark eyes separated by a cross-like spot. The oculiferous 

 tubercle is placed on the cephalic part of the first segment, between the two ovigerons 

 legs. 



The mandibles are very long, the first joint being much longer than the proboscis ; 

 the second joint is shorter and strongly curved, the claws being placed almost trans- 

 versely before the mouth. The immovable claw is more strongly curved than the 

 movable one ; the spines on the claws are numerous, l3ut they are almost equal and of 

 the same length. Both joints are covered with numerous small hairs, stronger ones being 

 found at the end of the first joint (PI. V. fig. 2). 



The palpi arc not very hairy. The second joint is l^y far the longest, the fourth is 

 the shortest, the fifth very slender. The whole length of the palpus is about twice the 

 length of the proboscis (PL V. fig. 1). 



The ovigerous legs of the males are not quite so long as the body. The fifth joint 

 is the longest, and is considerably swollen at the extremity, the sixth joint is a great deal 

 shorter, the seventh to the tenth joints are very short, the claw almost of the same length 

 as the last joint. The ovigerous legs are very strongly bent and not very hairy. The 

 denticulated spines of the four last joints are sharply serrated and not numerous, their 

 numbers being respectively 3, 3, 2, 3 (PI. V. figs. 3, 4). The claw is furnished with a 

 row of acute spines. 



The ovigerous legs of the females are still shorter than those of the males. The 

 relative length of the joints is the same, but the fifth joint is not swollen at the 

 extremity. The leg is not curvBd as is the case with that of the male. 



For a species of NymjjJion the true legs are uncommonly short : a female of 6 mm. 

 has a leg of only 14 mm. The second joint is not cpiite twice as long as the first or 

 third, the three following joints are almost of the same length, and comparatively robust, 

 especially the fourth joint of the female. The two tarsal joints, the second of which is 

 the longer, are very slender and almost smooth, together about as long as the sixth joint. 

 The claw is about as long as one-third of the length of the second tarsal joint, the auxiliary 

 claws are very small. The legs are very haiiy. These liaii's vary greatly in size and 

 strength, and are not placed in regular rows. The dorsal surface of the leg especially is 

 covered l.iy a large quantity of stronger spines. The genital pores of the females are very 

 large and visiljle on the second joint of every leg. Those of the males are small, and 

 found only on the second joints of the two last legs. 



