3 



t ounce ted l\ }, Ini< 



iift\ known. i.\,unple. /Y/- //>.//// I ;. 0- 



Diplopoda. Terrestrial, i . h-ad and body. I. 



usually cylindrical, with numeiou -.vhi< h are double 



and bear two pair- oi short limb>, which 



ventral line. implr. ;intcnn;i- -hort . usually BCVG 



. -/Yr;/>(///<\ 







mouth parts consisting of a pair of mandibles and a compound plate, 

 or Lrnathochilarium. Genital openings separate, anterior in position 

 (on the second segment of the body). Example, Spirobolus (Fig. 4). 



Pauropoda. Terrestrial. Two regions, head and body. Body 

 elongate, twelve-segmented, with nine pairs of functional legs; each of 

 the first five apparent terga consists morphologically of two united 

 terga. Eyes absent, but a pair of eye-like spots may be present. 

 An ten me characteristic; with four proxi- 

 mal segments and a pair of distal 

 branches bearing three filaments in all. 

 Mouth parts represented by mandibles, 

 m axil he (?) and labium (?). A single 

 genital opening (female) or a pair of 

 openings (male) on the third body 



u-nt. Minute arthropods, at most 

 about one millimeter in length. Example, 

 Pauropus. 



Chilopoda. Terrestrial. Two regions, 

 head and body. Body long and flat- 

 tened. with numerous segments, each of 

 which bears a pair of long six- or seven- 



segmented limbs, which are not inserted near the median line. Eyes 

 simple and numerous (agglomerate in Scutigera) antennae long, many- 

 segmented. A pair of mandibles and two pairs of maxillae. A single- 

 genital opening, on the preanal segment. Example, Scolopendra ^Fig. 5). 



Symphyla. Terrestrial. Two regions, head and body. II 

 prognathous, with a Y-shaped epicranial suture. Eyes few. Antenna' 

 multiarticulate. Four pairs of mouth parts; mandibles two- 



FIG. 4. A diplopod, Spirobolus 

 marginattis. Natural size. 



