504 
ARACHNIDES. 
Sub-Division I. — Tetrapneumones. 
Provided with two spiracles and two pulmonary sacs on each 
side.—Contains five genera :—4. Mygale; 5. Atypus; 6. Orio- 
don : 7. Filistata; 8. Dysdera. 
Genus 4.—MYGALE.— Latreille. 
Generic Character. — With protruding, elongated, pediform 
palpi, inserted at the point of the jaws; hooks of the mandi¬ 
bles bent downwards; jaws elongated; with a small quadrate 
lip; eight eyes. 
Mygale avicularia. —The Bird-Catching Mygale. 
Plate XCVI. fig. 3. 
Deep dusky-brown, covered with long hairs ; palpi and legs 
tipped with rust-colour; tarsi broad. Ten inches from the 
stretch of its legs. Inhabits South America. 
Sub-Division II.— Dipneumones. 
One spiracle, and one pulmonary sac only, on each side of the 
abdomen; six spinning orifices, the four outer ones somewhat 
square, and two smaller ones in the middle. 
TRIBE I_TUBITELJE. 
With cylindrical approximate spinning orifices, in a fasciculus, 
directed backwards; feet strong, the first and last two the largest, 
or vice versa. —Its genera are, 9. Clotho; 10. Drassus ; 11. Se- 
gestria; 12. Clubiona; 13. Aranea; and 
Genus 14. — A RG YR ONE T A_ Latreille. 
Generic Character. —With straight, elongate, quadrate max¬ 
illae, rounded at the apex; lip an elongated triangle, shorter 
than the maxillse; the second pair of feet shortest; eyes with 
the four central ones forming a quadrangle, the side ones placed 
obliquely. 
Argyroneta aquatica. — The Aquatic Argyroneta. 
Plate XCVI. fig. 4. 
Deep dusky-brown ; abdomen black, pilous, with impressed 
dots on its back. Inhabits slow running streams of Europe. 
