HANSEN AND SORENSEN: THE ORDER PALPIGRADI. 239 
nida) and Thysanura (with other Insects) are Condylopods, there 
is no closer affinity between Insects and Arachnids, or between 
Thysanura and Palpigradi: Arachnida occupy a very isolated 
position with regard to the other classes of Condylopods. No 
doubt, they come closer to Crustacea than to the other classes. 
But that Poeczlopoda should form the connecting link between 
Crustacea and Arachnida, we think is quite out of the question. 
EXPLANATION OF PLATE 4. 
Lettering. 
I—VI. Limbs. 
I—4 and 9—11. Abdominal segments. 
C, Head (the foremost part of the cephalothorax). 
Coxa. 
Femur, 
Supra-anal flagellum. 
ep dese Ian 
Hypostoma, 
i. Place of insertion of first pair of limbs, 
l. Labrum. 
m. Metatarsus. 
o. Mouth. 
p. Patella (wanting in second pair of limbs). 
rs. Supposed receptaculum seminis, 
s. Tactile hairs on third pair of limbs. 
sl, First couple of blade-shaped sensory hairs situated on the front, 
s*, Second couple of blade-shaped sensory hairs situated laterally on the head 
above the second pair of limbs. 
t', t?, First and second free thoracic segments. 
ta. Tarsus (s. str.). 
tibia. 
tr. Trochanter. 
Fig. 1. The animal seen from above, x 32. The last five joints of the 
supra-anal flagellum, which are shown in a fainter tint, were wanting 
in the specimen represented and have been added on Grassi’s authority. 
(When the animal is placed on an object-glass the antennæ cause 
that the dorsal surface of the »cephalothorax» is oblique, raising towards 
its anterior end, and the result of this position and of contraction 
produced by the influence of spirit is that the posterior median angle 
17 
