Scudder.J 252 [March 22, 



gracilis Stal, the structure of the abdomen is very different from that 

 of the male. The ultimate, penultimate, and to some extent the 

 antepenultimate dorsal segments are extremely short; and the forceps 

 also being short, it has the appearance of being partially withdrawn 

 within the body; the extremity of the abdomen is thus suddenly, 

 bluntly rounded, and the last segment, instead of being conspicuous, 

 as in the male, is scarcely visible at all above; beneath it is rather 

 shorter than the others, its extremity broadly and regularly convex. 

 As the tegmina and wings of both the females are wanting they 

 may be immature, but they are otherwise so perfectly formed, and 

 the metathorax resembles so closely that of the wingless genera, that 

 I take them for perfectly developed insects, and conclude that the 

 females of this genus are apterous. 



42. Labidura auditor. This species differs from L. riparia 

 principally in the character of the forceps. In the male these are 

 more strongly and regularly arcuate than in L. riparia, not in the 

 least curved upward, but lying in a horizontal plane, the middle 

 tooth small, and scarcely affecting the curve of the interior edge of 

 the forceps. In the female they curve downward rather than up- 

 ward, and curve inward toward the tip more strongly than usual in 

 L. riparia. The wings in both sexes are altogether wanting. In 

 size, color, markings and sculpture, it altogether resembles L. riparia. 

 1 d, 1 ?. Natal. 



43. Chelisoches comprimens. Head piceous, smooth, the 

 middle of the front a little tumid; mouth-parts dark reddish brown; 

 basal joint of antennae blackish, joints two to thirteen gradually 

 growing paler, the three following pale yellow, and the remain- 

 ing (eight or more) pale brownish fuscous. Prothorax blackish cas- 

 taneous, the sides slightly marginate, a distinct sharp median sulca- 

 tion and a dull semicircular sulcation uniting the front outer angles. 

 Tegmina and exposed part of wings dark castaneous, the latter less 

 than half as long as the former, together twice as long as the pro- 

 thorax; tegmina docked with a sinuous curve, much as in C. morio 

 (Fabr.). Legs dark castaneous, the tarsi luteous. Abdomen dark 

 castaneous, profusely punctate, the posterior edges of the segments 

 indistinctly beaded; lateral plications of second and third segments 

 more distinct than in C. morio, and the whole abdomen not so slender 

 as in that species. Forceps almost precisely as in C. morio, rather 

 longer, and of the color of the abdomen. Length of body, 12 mm.; 



