SYSTEM OF INSECTS. 397 
suborders, — the Sedentarics and the Wanderers ; thus 
forming, perhaps, what Mr. MacLeay would denominate 
the normal groups of a circle of AracJmida. 
Def. Mandibles armed with a perforated claw. 
Head and Trunk coalite. 
Palpi pediform, anterior pair without claws. 
Abdomen without segments or elongated tail. 
Spiracles two a . 
Anus furnished with an apparatus for spinning 5 . 
2. Scorpionidea M C L. (Scorpio L. Latr.) 
Def. Mandibles chelate. 
Head and Trunk coalite. 
Anterior Palpi chelate c . 
Posterior Palpi pediform. 
Pectens two d . 
Abdomen divided into segments and termina- 
ting in a jointed tail, armed at the end with a 
sting e . 
Spiracles four pairs. 
3. Gale ode a. 
Def. Head distinct f . 
Eyes two. 
Mandibles chelate with dentated chelae. 
a Plate XXIX. Fig. 1. b Plate XV. Fig. 10. T". 
Plate XXIII. Fig. 15. 17. T". c Plate XV. Fig. 7. 
A Plate XXVII. Fig. 50. 
« Called the Centris. Vol. III. p. 388, 716. 
f M. Latreille thinks that in Galcodes the prothorax is coalite with 
the head {N. Diet. d'Hist. Nat. xii. 370.) ; but that it is not so, is evi- 
dent from the six real legs being affixed to the pieces behind it. See 
also Vol. III. p. 23. note 11 . 
