68 Annals of the South African Museum. 



Sedgwick, 1888&, fig. 27, in which three such pieces are drawn, 

 while in each of my figures, 6 and 6a, only the outline of one of four 

 pieces has been given). Obviously new jaws are continually being 

 formed within the outer ones, which drop off from time to time, and 

 there are generally two or three such reserve jaws within each outer 

 one. Similar reserve jaws are also known in other forms. 



2. The papillce. 



The papillae of the skin are best studied in drowned specimens 

 and in sections. Each large papilla in drowned specimens is seen 

 to be composed of a conical proximal portion and a darker and rather 

 sharply marked-off distal portion. The distal part is either cylin- 

 drical (fig. 8c) or it is incrassated towards the apex (fig. 8b), which 

 is somewhat flattened and bears a spine in its centre. On the legs 

 long slenderer papillae (fig. 8a) are also found. In spirit specimens 

 the conical basal part of these papillae is less evident, while the apex 

 is often much flatter. Pig. 8d represents one of the smaller, club- 

 shaped, flat-topped papillae of the upper surface, common in spirit 

 specimens. 



For comparison outlines of the large papillae from the sides of the 

 body in P. halfouri (fig. 9) and P. capensis (fig. 10) are given. 



The shape, structure, and distribution of the papillae has recently 

 been shown by Bouvier (1900a) to possess considerable systematic 

 value in the American forms. I believe they will be found to afford 

 some valuable characters in the South African species as well, when 

 more carefully examined than has hitherto been done. For this 

 purpose, however, it is necessary that only specimens which have 

 been preserved in a similar manner be compared with one another, 

 as the papillae are liable to alteration in shape. 



3. The legs. 



I counted the legs in about thirty specimens and invariably found 

 only 16 pairs. As in Perijmtopsis, the legs diminish slightly in 

 size towards each end of the body, but the last (genital) pair is sub- 

 equal to the first pair of legs and is always perfectly developed and 

 provided with 3 spinous pads ; in this and in several of the pre- 

 ceding pairs, however, the proximal pad shows indications of its 

 origin from a row of large papillae (fig. 11). The actual size of the 

 last pair of legs varies considerably in spirit specimens, these legs 

 being sometimes large and long, sometimes much smaller and 

 shorter, but as this is equally the case in both sexes these dif- 



