A Monograph of Scytonotus. 243 



Comparative Differences Behveen the Sexes. 



1. The antennae of the female are shorter and more clarate than 

 those of the male (of figs. 40 and 41). 



2. The legs of the female are about one-third shorter, and about 

 half as thick as those of the male (cf figs. 1-29 and 30-30), 

 These difterences are sufliicient to make the sexes distinguishable 

 at sight, the female appearing much more slender, though the 

 diameter of the body is not less than in males. 



The size and shape of the first pair of legs is nearl}^ the same 

 in the two sexes (cf. figs. 1 and 3), and the coxal joint is in both 

 cases densel}- papillose, except on its posterior face. The differ- 

 ence in size between the sexes begins to appear in the second legs, 

 whose coxa? are papillose on the outer face in both sexes. Oc- 

 casionally the coxa? of other male legs show a slight roughenins; 

 of the outer face. 



3. The pedigerous lamina? of females are much broader than 

 those of males (fig. 62), a partial compensation for the shortness 

 of the female legs. 



Secondary Sexual Characters of Males. 



1. Legs 13-20, '^ inclusive, are more or less conspicuously dif- 

 ferent from the others, some of the joints being more crassate 

 and otherwise modified. The legs increase in size gradually 

 from the 1st to the 13th, the penultimate joint of which is much 

 inflated, as is also that of the 14th, 19th and 20tli, and to a less 

 degree that of the 15th, 16th, iTth and 18th. The 21st legs are 

 apparently different from the 12th. The legs behind the 21st pair 

 are gradually more slender and slightly shorter. In the legs 

 which are most modified, the 13th, 14th, 19th and 20, the last 

 joint is shorter than the normal, the penultimate being hj-per- 

 trophied. 



2. The ventral face of the distal portion of the second joint is 

 papillose on the 18th, 19th and 20th legs. The papilla? are few- 

 est on the 18th and most numerous on the 19th, on which also 

 the papillose surface is considerabl}' elevated, the same condition 

 obtaining on the 20th, but to a less degree. 



' The drawings of the male legs are numbered as they occur on the 

 animal. 



