215 



fully abdoininal ; the inner nearer the edge than the median 

 line, are very long, about 1 1 / 2 times the length of the body ; 

 the outer pair much shorter, close to the edge. The sixth row, 

 strougly curved baekward, is quite marginal; the inner pair is 

 far the longer. 



Ventral side (Fig. 22). Epimera I joined to a short sternum. 

 Sternum about one third the length of epimera I. Epimera II 

 proximally (i. e. near the median line) a little curved baekward, 

 as long as epimera I and parallel to them. Epimera III short but 

 distinct, forming the outer and anterior limit of coxal plate III. 

 Epimera IV only represented by a short chitinous bar, forms the 

 inner and posterior limit of coxal plate III. Moreover a chitinous bar 

 limits the inner and anterior end of coxal plate III. This bar is a part 

 of the long bar that limits posteriorly coxal plate II of the hypopus 

 (see fig. 17 and 20). — Genital aperture small, oval, shut by an oval 

 valve, at a level with coxae III, limited in front by a chitinous 

 apparatus, almost like an X with small head and large legs, and 

 posteriorly by a chitinons little bar, curved baekward. Suckers 

 very small. Anal aperture large, closed by 2 valves, which sur- 

 pass the posterior margin slightly. Hairs; small smooth hairs are 

 to be found: on the coxal plate I; before and to the sides of the 

 genital aperture; at the level of distal end of coxal plate IV; before 

 and to the sides of the anal aperture. Hairy, long hairs: between 

 coxae II and III a hair very close to the edge of the body ; and 

 quite posteriorly 4 pair of hairs also very close to the edge of 

 the body ; of the latter hairs the second (counted from the anus) 

 are the smallest, the three other almost equal in length and about 

 that of the body. 



General observations about the length of the hairs. In general 

 the length of the hairs increase from before to behind. In general 

 the first 4 dorsal transverse rows are short, the last 2 are loug. 

 In general the short hairs are shorter than the width ot the body, 

 and the long hairs as long as or even longer than the body. But 

 in different individuals the relative lengths of the hairs may be so 

 different, that at first one is inclined to believe there are different 



