398 SYSTEM OF INSECTS. 
Palpi pediform, the anterior pair thickest with 
a retractile sucker. 
Trunk consisting of two principal segments, 
with a minute supplementary posterior one a . 
Spiracles two placed in the trunk b . 
Pseudo-pcctens two c . 
Abdomen divided into segments. 
Anns unarmed and without a spinning appa- 
ratus d . 
4. Phuynidea. 
Def, Mandibles unguiculate. 
Anterior Palpi chelate or unguiculate e , very ro- 
bust. 
Posterior Palpi pediform, very long and slender. 
Abdomen divided into segments. 
Spiracles two pairs. 
Anus terminating in a mucro, and sometimes in a 
filiform jointed tail without a sting at the end. 
v. Having; considered the Orders into which Insecta 
and Arachnida may be divided, I am next to give you 
some account of the groups into which each is further 
resolvable. To draw out, however, a complete scheme 
of these would be deviating from my province, and ex- 
a L. Dufour ubi supr. IV. iii. 18. b Ibid. 19. 
c Ibid. t. lxix./. 7. d. 
<i When the characters of the Class Arachnida were drawn up 
(Vol. III. p. 30.) I had not seen a Galeodes : they should he thus 
amended : 
Palpi four : anterior pair pediform, cheliform, or unguiculate ; 
posterior pediform. 
Trunk Legs six, &c. 
■ Plate XIII. Fig. 1. 
