AN AMPHIPOD FROM THE TRANSVAAL. 953 



three plumose seta? on its inner margin, and distally three short 

 stout bristles and about eleven plumose sette. The endite of the 

 ischiopodite or outer plate carries a number of fairly short stout 

 bristles distally, and along two-thirds of its inner margin six of 

 the distal bristles are serrated. 



Gnathopods : about the same size and length ; the fifth and 

 sixth joints of gnathopod I. somewhat broader than those of 

 gnathopod II. In the male, gnathopod I. is a little longer than 

 gnathopod II. 



Gnathopod I. (PI. L. fig. 9) well developed, subchelate ; the 

 coxa of the first joint in shape making almost a parallelogram, 

 sloping forward somewhat, anterior portion deeper than posterior^ 

 diagonal from posterior ventral corner to anterior dorsal corner 

 equalling greatest length of coxa ; anterior margin bearing five 

 small spines and ventral margin five also. The second joint or 

 basos is narrow at the base, has anterior side straight, and bears 

 six feebly serrated setso, the most distal the longest ; posterior 

 margin convex, most markedly about the middle of the joint 

 which is here seen to be two-fifths in breadth to length ; the 

 posterior margin carries a number of long sette, and following 

 this arrangement, four setae proximally, equidistant apart, followed 

 by a group of two, then a group of three, a grouj) of two, another 

 group of three setfe all serrated, and distally a group of four 

 smaller setfe, not serrated. The third joint or ischium is shoi-t, 

 broader than long, and bears on its posterior distal extremity five 

 setse not serrated. The fourth joint or meros has the posterior 

 distal portion rounded and well provided with nvimerous serrated 

 setse, proximal to which lie a grouj) of four serrated setae ; on the 

 anterior margin four small set* can be noticed. The fifth joint 

 or carpus, which is more or less triangular, has a dense cluster of 

 serrated setae on its short posterior portion, which are arranged 

 into groups, one consisting of a row of marginal setae, another of 

 apparently two rows placed submarginally ; the anterior margin 

 of the joint carries four setae. The sixth joint or propodos is 

 subovate, equal in length to the longest measurement of the basos, 

 as wide as the greatest vertical depth of the coxa ; anterior margin 

 convex, with four groups of four fairly short setae arranged at 

 varying intervals from a fifth group of six longer setae sitiiated 

 near the base of the dactylos ; in addition, a small solitary seta 

 will be noticed external to the third of these groups ; the posterior 

 margin, starting from the proximal end, is straight for a short 

 distance, to a part where four small well-marked prominences are 

 encovintered ; on each of these are placed two finger-shaped pro- 

 cesses of unequal length and, excepting on the last prominence, 

 two setae ; behind the fourth prominence lies a row of setae : the 

 palm, to which the dactylos fits closely, follows immediately ; it is 

 provided with a series of very short spines arranged in couples, 

 each couple equidistant apart ; a number of short setae, nine in 

 number, are also present opposite the border of the most posterior 

 muscle, disposed more or less in a straight line, and varying 



