106 
Guide to Arachnida. 
Table-case 
No. 24. 
Sub-order I.— PANCTBNODAOTYLI. 
The members of this sub- order have the first appendage of 
small size, and the serrula of the movable finger is fused through- 
out its length to the finger. 
There are three families : (1) Garypidae, (2) Feaellidae, (3) 
Cheliferidae. Specimens of a large species of Chelifer from Sierra 
Leone are exhibited in Case 24. 
Sub-order II.— HEMICTENODACTYLI. 
The first pair of appendages of the Hemictenodactyli is of large 
size, and at least the distal end of the serrula of the movable 
finger is free. 
There are two families : (1) Chthoniidae, (2) Obisiidae. 
Order 7.— Podogona. 
Owing to a close, but superficial resemblance to certain species 
of Opiliones the Podogona were regarded, until quite recently, as 
forming part of that order. The 
anterior of the two plates, which 
form the carapace of the cepha- 
lothorax (prosoma), is of small 
size and forms a movable hood, 
which covers the mouth and 
first pair of appendages. The 
palps are weakly chelate. A 
movable membranous joint 
unites the cephalothorax and 
the abdomen, the genital aper- 
ture opening upon the ventral 
surface of this membrane. The 
abdomen (opisthosoma) consists 
of only four visible segments, 
in addition to a tubular ring 
encircling the anus. A striking 
the position of the copuiatory 
at the end of each walking-leg 
Diagram of a species of Cryptostemma, 
to show the characters of the 
Podogona. ( X 4.) 
peculiarity of these animals is 
organs, one of which is placed 
of the third pair. A single pair of respiratory spiracles, which is 
situated towards the posterior end of the cephalothorax, is present. 
A specimen of a West African species ( Gryptostemma harschi) 
(and also enlarged drawings of the species) are also exhibited in 
Table-case 24. 
