Podogona, Opiliones 
107 
The existing species of Podogona are referable to the family Table-case 
Gryptostemmatidae. They are small Arachnids, barely reaching • No - 24 - 
half an inch in length, and are confined to the forest-clad tracts of 
tropical West Africa and Brazil. 
The group was represented in the Carboniferous period by the 
genus Poliochera. 
Order 8.— Opiliones (Harvest-men). 
In the Opiliones the “ cephalothorax ” is confluent with the Table-case 
abdomen throughout its width, and its carapace is either unseg- No- 25 
mented or divided into two segments. Paired stink-glands open 
on its dorsal surface near the 
lateral margins. The palp is 
not chelate. The abdomen is 
clearly segmented, the somites 
sometimes numbering as many 
as ten. Respiration is carried 
on, as in the Pseudoscorpions, 
by means of tracheal tubes 
which open by a pair of 
stigmata on the sternal plate 
of the abdomen. 
Most of the Opiliones are 
of rather small size, but some 
of the South American species 
reach considerable dimensions. 
They are exclusively carni- 
vorous, feeding upon insects, 
worms, and the like. The 
female lays her eggs in crevices 
of the soil, or any damp place, 
and leaves them to their fate. 
The extinct Arachnida known as the Anthracomarti, which 
occur in the Carboniferous strata, are perhaps allied to the Opiliones. 
A cast and drawings of one of these fossil forms are exhibited in the 
Table-case (No. 25) with the Opiliones, and several casts and 
specimens are shown in the Geological Department (Gallery 8, 
Table-case 23). 
Sub-order I. — LANIATOEES. 
In these Opiliones the palp is often stout and furnished with a 
strong prehensile claw. There is a single claw on each of the 
Fig. 70. 
Gonyleptes chilensis. 
