388 SYSTEM OF INSECTS. 
they are organs of the part representing the head, and 
therefore not in a primary sense legs; although in a se- 
condary, as M. Savigny has proved, they may be so 
called #4. 
1. AranipEa MCL. (Aranea L., Araneide Latr.) The 
Aranidea, or spiders, seem resolvable into two suborders, 
—the Sedentaries and the Wanderers; thus forming, per- 
haps, what Mr. MacLeay would denominate the normal 
groups of a circle of Arachnida. 
Der. Mandibles armed with a perforated claw. 
Head and Trunk coalite. 
Palpi pediform, anterior pair without claws. 
Abdomen without segments or elongated tail. 
Spiracles two®. 
Anus furnished with an apparatus for spinning *. 
2. ScoRPIONIDEA M‘L. (Scorpio L. Latr.) 
Der. Mandibles chelate. 
Head and Trunk coalite. 
Anterior Palpi chelate‘. 
Posterior Palpi pediform. 
Pectens two*. 
Abdomen divided into segments and termina- 
ting in a jointed tail, armed at the end with a 
sting’. 
Sptracles four pairs. 
« Meém. sur les Anim. sans Vertebr. 1.3. 57—. 
> Prats XXIX. Fie. 1. ° Pram XVi Bre. 10sg 
Prare Xero. lige ce a PLATE XV. Fie. 7. 
© Prate X XVII. Fic. 50. f Called the Centris. Vox. III. 
p. 389, 717. 
