THYSANURA. 



137 



FIG. 200. Abdominal 

 legs of Campodea. 



SUB-OilDER III. - - ClNURA. 



Like those of the last, the forms in this group are frequently much larger than the 

 podurids. The mouth-parts in many respects resemble those of the Orthoptera, and 

 the abdomen is provided with imperfect or abortive legs. From 

 the long abdominal appendages these forms receive their scientific 

 name, which may well be translated into a more popular form, 

 bristle-tails. 



The family CAMPODE^E comprises two genera, which are quite 

 dissimilar in form. The group is distinguished by the long, slender 

 body, and by the mouth-parts, jaws, etc., being still withdrawn 

 mostly within the head. The common form is Campodea, and C. 

 fragilis is found everywhere under stones in shaded, damp places. 

 It is yellowish-white, its antennae long and slender, and its body 

 ends in two long caudal jointed threads, about a sixth of an inch 

 long. It looks at first sight like a young centipede (Lithobius), and 

 is very agile in its movements. A much larger species ( C. Cookei), 

 and also differing in having longer antennas, inhabits Mammoth 

 Cave. 



lapyx is the other genus of this family. It is rather more highly 

 developed than Campodea, and differs in the body ending in a pair 



of stout forceps. While Campodea has a series of 

 little one-jointed movable appendages along the under 

 side of the body lapyx has none. Our North Ameri- 

 can species is lapyx subterraneus, which is found 

 under stones at the mouth of a small grotto near Mam- 

 moth Cave. Another species occurs in Mexico. 



We now come to the bristle-tails proper (LEPIS- 

 WATID^E). These agile creatures are seen gliding 

 swiftly over the floor or walls of damp rooms or over 

 outhouses, or running away rapidly from under up- 

 lifted stones. The body is long and slender, either 

 flattened or cylindrical, and covered with metallic 

 scales. Their antenna are long and thread-like ; their 

 jaws and feelers (palpi) are well-developed, and in 

 general like those of cockroaches. The caudal stylets 

 or filaments are very long, and usually finely bristled. 

 These insects run with great swiftness, and in their 

 structure, especially of their body-segments and leu-, 

 as well as their motions, they remind us of immature 

 cockroaches. 



In the genus Lepisma there are seven caudal 

 bristles, of which three are longer than the others. 

 The peculiar motions of these animals are due to 

 the nature of the legs, the tarsal joints being much as in cockroaches, broad, flat, and 

 almost triangular. A common species in damp, shut-up apartments is Lepisma sac- 

 charina. It has somewhat the habits of the cockroach, eating clothing, tapestry, the 



FIG. 201. Campodea. 



