Symphypleona Protura. 83 



1. Furcula wanting; body naked or hairy, never with scales; antennae four-jointed, 



often poorly-developed; claws two or one; sluggish species. (Anurida, 



Neanura) (ANURIDIDM) APHORURDXE 



Furcula present 2 



2. Furcula attached to the penultimate abdominal segment; body sometimes 



clothed with scales; antennas four- to six-jointed; claws two. (Is6toma, 

 Orchesella, Tomocerus) (PL 16, figs. 380, 381). 



(DEGEERIID&) ENTOMOBRYID^E 



Furcula attached to the antepenultimate abdominal segment; body without 

 scales; antenna four-jointed; claws two or one. (Podfcra, Achortites.) 



(ACHORUTIDfi) PODURnXffi 



ORDER SYMPHYPLEONA. 



Body shortened; abdomen globose, its segments in part fused; 

 head usually vertical; ventral tube always long and well developed, 

 usually with two long, exsertile filaments; furcula well developed; 

 no post antennal organ; heart with two pairs of ostioles. 



1 . Last joint of the antennae long, usually divided into false ring joints (annul!) ; 



upper claw unindentate. (Sminthurus.) (PL 16, fig. 384). 



SMINTHURIIXE 

 Last joint of antennae short, not ringed 2 



2. Last joint of antennas with whorls of hairs; the distal part of the third joint 



annulate; head vertical; filaments of ventral tube long; thorax shorter than 



the abdomen. (Papfrius.) PAPIRfaD^ 



Distal joints of antennae simple; head horizontal; filaments of ventral tube 

 represented by two rounded tubercles; thorax longer than the abdomen. 

 (Neelus, Megalothdrax.) (MEGALOTHORACIDfi) NEELIDJE 



CLASS MLRIENTOMATA. 



Minute, delicate, wingless, terrestrial, blind species. Body 

 bare; antennae absent, abdomen comprising eleven segments and 

 a short anal tube, the basal three segments furnished with styles; no 

 cerci; mouthparts, formed for sucking, but retracted within the 

 head. 



[ORDER PROTURA. 



f Slender, head pear-shaped, labrum medially narrowed to a 

 beak, mandibles long and slender; prothorax short; legs short, 

 tarsi one-jointed. 

 (Eosentomon) (PL 16, fig. 385) EOSENTOMDXffi 



