ClilLOGNATIIA EfSECTA. 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. Polyzoniwni germanicum 

 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 pl.ates. The limbs meet together in the middle ventral line. 

 Jvlus sabidosus L. 



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

 plates. The number of somites is small. Polydesmus cowplanatus Deg. } 

 Polyxenus lagums L., with twelve pairs of legs. Pauropus Huxley I Lubb. 



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

 ball. There are ^nly 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 marginata 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. Svharotherivm elongatum Brdt. 



Class V. HEXAPODA*=INSECTA. 



Tracheata with two 

 antennae on the head, 

 and with three pairs 

 of legs and usually 

 two pairs of wings 

 on the thorax, which 



latter is composed of ^ ^ 



three segments; the ^\^St St 



abdomen has nine or FIQ 428 ._ Head> thorax and abdcmen of an Acrldium 8ee7] 



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



* J. 'Swammerdam, " Historia Insectorum generalis," Utrecht, 1669. J. 

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

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

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

 sectenbelustigungen," Niirnberg, 1746 to 1761. Ch.de Geer, "Me"moires pour 

 servir a 1'histoire des Insectes," 8 vols., 1752 to 1776. H. Burmeister, " Hand- 

 buch der Entomologie," Halle, 1832 



