CliLLOGNATUA INSKCTA. 521 



segment of the body, at some distance from the genital openings. 

 In Glomeris, this copulatory organ seems to be replaced by two 

 accessory pairs of appendages on the anal segment. The young 

 possess at first only three pairs of legs, and the metamorphosis would 

 therefore seem to be more complete than in the Chilopods. 



The Chilognatha live in damp places, beneath stones on the 

 ground, and feed on vegetable and dead animal matters. Many of 

 them roll themselves up into a ball like the woodlice or into a spiral. 



Fam. Polyzonidae. With small head and subcylindrical body -which can be 

 rolled up into a spiral, and suctorial mouth parts. Polyeoniitm gcrmanicinn 

 Brdt. 



Fam. Julidae. The head is large and free. The eyes are mostly aggregated 

 together ; with cylindrical body, which can be rolled up in a spiral ; without 

 broad dorsal plates. The limbs meet together in the middle ventral line. 

 Jiilus sabulosi/s L. 



Fam. Polydesmidae. With large free head and laterally extended dorsal 

 plates. The number of somites is small. Polydesmus complanatus Deg. 

 Ptilyxemts la gurus L., with twelve pairs of legs. Pauroptis Hu.dcyi Lubb. 



Fam. Glomeridse. The body is short and broad, and can be rolled up into a 

 ball. There are only twelve to thirteen segments, which possess dorsal plates. 

 The last ring of the body is shield-like. They remind one of the genus 

 Armadillo. Glomeris viarginata Leach., with seventeen pairs of legs ; in the 

 male there are in addition two pairs of genital appendages at the hinder end 

 of the body. SvlicsrotJierium elontjatum Brdt. 



Class V. HEXAPODA*=INSECTA. 



Tracheata with two 

 untennce on the head, 

 and with three pairs 

 of legs and usually 

 two pairs of ivings 

 on the tJiorax, which 

 latter is composed of 

 three segments ; the, 



abdomen has nine or FIQ 428 _ Head> thorax and abdomen of an AcrMium eeei) 

 ten Segments. from the side. St, Stigmata ; T, tympanic organ. 



* J. Swammerdam, " Ilistoria Insectorum generalis," Utrecht, jl>09. J. 

 Swammerdam, " Bijbel der natuure," 1737-1738. Reaumur, " Mcmoires pour 

 servir a 1'histoire des Insectes," 12 vols.. Paris, 1734-1742. Oh. Bonnet, 

 "Traite d'Insectolopie," 2 vols., Paris, 1740. A. Rb'scl von Rosenhof, "In- 

 secteiibelustigungen," Nurnberg, 1740 to 1701. ch.de Gccr, " Meiuoires pour 

 servir a 1'histoire des Insectes," 8 vols., 1752 to 1770. H. Burmeister, " Hand- 

 buch der Entomologie," Halle, 1832 



