MESOCHRA. 63 



with rows of thickly set, short spines (PI. XLI, fig. 21), 

 last segment short and destitute of spines, caudal 

 segments a little longer than broad. Anterior antenna 

 of the female short, the joints of nearly equal size, the 

 third and fourth being, however, slightly longer than 

 the rest (PL XLI, fig. 15). In the male the anterior 

 antenna is short and thick (fig. 16), corrugated and 

 obtuse, ending in a small aborted claw. Posterior 

 antenna 2-jointed (fig. 17), and having a very small 

 1- jointed branch attached to the middle of the inner 

 margin of the first joint. Second pair of foot-jaws 

 (fig. 19) small, terminal claw long and slender. First 

 joint of inner branch of first pair of feet (PL XL VII, 

 fig. 17) longer than the entire outer branch, with 

 ciliated margins, and bearing below the middle of the 

 inner margin a moderately long seta ; last joint (coale- 

 scent second and third joints, Boeck) short, and 

 armed with two long and strong apical setae ; the three 

 joints of the outer branch with strong apical spines 

 and fringed margins, middle joint fringed also on 

 the inner margin, the three terminal setae of last 

 joint geniculated. First joint of the inner branch in 

 the three following pairs of feet not very much 

 smaller than the second joint (PL XL VII. figs. 18 

 20). Inner segment of the basal joint of fifth pair 

 long and broad (fig. 21), and having six stout setae of 

 various lengths; second joint rather small, sub- quad- 

 rangular, and bearing five setae, the longest of which 

 are plumose. In the male the fifth foot is much smaller 

 (PL XLI, fig. 20), and the inner segment of the basal 

 joint has only three setae. The anal operculum is 



