ATA Mr. BLACKWALL on the 
have a considerable degree of curvature, and taper gradually 
to a fine point; those of the lower row being stronger, more 
closely set, and less curved. Inclined towards each other, the 
two sets, in the performance of their functions, describe a series 
of acute angles whose vertices are directed down the joint. 
This important appendage constitutes a striking specific charac- 
ter, which ought on no account to be omitted in descriptions 
of Clubiona atrox. 
When the spider purposes to form a flocculus, it presses its 
spinners against one of the glossy lines composing the founda- 
tion of its snare, and emitting from them a small quantity of 
liquid gum, attaches to it several fine threads, drawn out by ad- 
vancing the abdomen a little, and kept distinct by extending 
_ the mammule laterally. The foot of one of the hind-legs is 
then applied to the superior part of the upper tarsal joint of the 
other hind-leg, a little above its articulation with the lower joint 
of the tarsus, and the curious apparatus of spines, above de- 
scribed, is brought immediately beneath the spinners at right 
angles with the line of the abdomen. By a slight extension of 
the joints of the hind-legs the apparatus is forced backwards 
across the mammule, the diverging extremities of which it 
touches in its transit, and is restored to its former position by 
a corresponding degree of contraction in the joints. In pro- 
portion to the continuation of this process, (and it is not at all 
unusual for the spider to pass its spiny apparatus across the 
points of the mammul several hundred times in rapid succes- 
sion,) the inflected lines of the flocculus are found to be pro- 
duced, the spider making room for them as they accumulate, 
by elevating and at the same time advancing the abdomen in a 
small degree, which it effects by slightly extending the joints of 
the third pair of legs, and contracting those of the two anterior 
pair. As this operation is generally accomplished in the night, 
it 
moi 
e 
s. 
a 
A 
