been found in West
Africa and South America. A fact of special interest in regard to them
is that the genus Poliochera, from the Coal Measures, appears to be a
member of the same group. The name Cryptostemma, given to the
first-known genus of the order, described by Guerin-Meneville, refers
to the supposed concealment of the eyes by the movable cephalic
sclerite. Reference to literature (38).

[Illustration: FIG. 75.--_Cryptostemma Karschii_, one of the Podogona.
Ventral view.

I to VI, The six pairs of appendages of the prosoma, the last three
cut short.
1, 2, 3, 4, The four somites of the opisthosoma.
a, Visible hood overhanging the first pair of appendages.
b, Position of the genital orifice.
c, Part of 3rd appendage.
d, Fourth segment of 2nd appendage. Observe that the basal segment
of appendage III does _not_ meet its fellow in the middle line.

(Original drawing by Pocock and Pickard-Cambridge.)]

[Illustration: FIG. 76.--_Cryptostemma Karschii_. Extremity of the
fifth pair of appendages of the female for comparison with that of the
male E in fig. 73.]

Order 8. Opilione (see fig. 77).--Dorsal area of prosoma covered by a
single shield usually bearing a pair of eyes. Sternal elements much
reduced. Appendages of 1st pair large, three segmented and completely
chelate; of 2nd pair either simple and pediform, or prehensile and
subchelate; of remaining four pairs, similar in form, ambulatory in
function; the basal segment of the 2nd, 3rd and sometimes of the 4th
pairs of appendages furnished with sterno-coxal (maxillary) lobe.
Opisthosoma confluent throughout its breadth with the prosoma, with
the dorsal plate of which its anterior tergal plates are more or less
fused; at most ten opisthosomatic somites traceable; the generative
aperture thrust far forwards between the basal segments of the 6th
appendages. Prae-genital somite suppressed. Respiratory organs
tracheal, opening by a pair of stigmata situated immediately behind
the basal segments of the 6th pair of appendages on what is probably
the sternum of the 2nd opisthosomatic somite and also in some cases
upon the 5th segment of the legs.

Intromittent organ of male lying within the genital orifice.

Sub-order a. Laniatores.--Orifice of foetid glands opening above the
coxa of the 4th appendage, not raised upon a tubercle. Orifice of
coxal gland situated just