AN AMPHIPOD FROM THE TRANSVAAL. 955 



distally a group of three small setfe ; the posterior margin is pro- 

 vided with four groups of setfe. the proximal group consisting of 

 three setse, the next of two, then another of two, the most distal 

 group of four medium and one large seta. The sixth joint, which 

 is slender, bears on its posterior margin six groups of three setas 

 to each group, and on its anterior margin three minute setae, and 

 distally a grovip of four setae. 



PereiojMcl II. is practically similar in all respects to pereiopod I., 

 to which it is subequal ; on the second and third joints there are 

 two or three small additional setae marginally. 



Of the remaining jjereiopods the fifth is the longest, the third 

 the shortest, these differences of length being appreciable but not 

 great ; they are, however, considerably longer than the first and 

 second. In the third pereiopod, although the second and third 

 joints are somewhat shorter than those of the first pereiopod, the 

 great difierence in length is made up by the much greater length 

 of the fourth, fifth, sixth, and seventh joints of the third pereiopod ; 

 at the same time these four joints, though slender, are of the same 

 breadth as those of the first pereiopod. 



Pereiopod III. (PI. LI. fig. 12) : the coxa of the first joint is 

 somewhat concave anteriorly, emarginate posteriorly ; anteriorly 

 and ventrally it bears some small spines. The second joint is 

 rather narrow at the base, broadens very rapidly, and then 

 narrows gradually towards its distal extremity ; it is a little more 

 than twice as long as broad ; the anterior margin is slightly 

 convex and is beset with a number of moderate spines — describing 

 from the proximal end, three single ones equidistant apart, six in 

 pairs subequidistant ajmrt, and terminally a grovip of three spines : 

 the posterior margin has fourteen shorter spines equidistant apart 

 and terminally two closer together ; behind these latter a large 

 spine. The third joint is slightly I'ounded and carries a group of 

 four fairly small setae. The fourth joint is broader at the base 

 than that of the first pereiopod ; the anterior margin carries nine 

 small setae, arranged in pairs all but the most proximal, and 

 distally a group of four setae, one conspicuously larger than the 

 others ; the posterior margin carries two moderate spines and 

 three small ones and distally two fairly large and two small spines. 

 The fifth joint is armed with five groups of spines, the most 

 proximal group of two, the next three of thi'ee, and the following 

 of two spines to each group, and distally with a sixth groitp made 

 up of two larger and two smaller spines ; opposite the last group 

 is a group of one larger and three smaller spines, some distance 

 behind which is a single spine, and behind this spine again two 

 groups of three spines, and disposed proximally to these a couple 

 of small spines close together. The sixth joint is conspicuous on 

 account of the larger size of some of the spines on its anterior 

 margin ; on this margin four groups of three spines to each are 

 fixed, and distally a group of eight spines varying. in length : on 

 the opposite margin six gi-oups of spines are seen, each group 

 possessing two or three spines. The seventh joint, including the 



