36 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 
The spinning field, SF, is an elliptical slope, which is situated on the 
inner side of the spinneret, and extends across the summit to the opposite 
face of the tip. The basal part of the spinneret is cylindrical 
and gradually grows smaller toward the spinning field. At the 
lower or inferior edge is a row of long, strong branched bristles, 
bb. On the inner surface, and at the border of the prolonged spinning 
field, is a group of much shorter, stiff, simple bristles, sb. 
On each posterior spinning field is placed a number of spools, which 
may be estimated roundly at one hundred and twenty. Besides these, there 
are five larger spools, sp, which after Bucholz and Landois we may dis- 
tinguish as spigots. Through these spigots issue a corresponding number 
of cylindrical and treeform glands presently to 
be described. That part of the spinning field 
which runs downward toward the base is com- 
posed of numerous rows of long, closely placed 
spools, l.ss.; while that part of the field on the 
summit is covered with short spools, s.ss. (See 
Fig. 23.) Of the spinning spigots (Fig. 23), 
four stand close together in one group towards 
the middle of the spinning field, and one of - 
them is situated in the lower part of the field 
(near l.ss.), and appears to be covered by the 
long spinning spools. Of the four grouped 
spigots, three give exit to treeform glands; and 
the one farthest towards the base is connected 
Fic. 24. Middle spinneret, largely mag- with a cylindrical gland. The isolated spool 
nified. sp.c, spigot discharging cylin- = 
drical gland; ss, and s.ss, spinning SP, (near l.ss,) also discharges a treeform gland. 
oP hector gland) Pu spigoy = The middle spinnerets are of a three faced 
pyramidal form. (Fig. 22, M, and Fig. 24) 
The bases are directed towards the front, while their points, lying closely 
together, are turned immediately backward. They are unjointed.' The 
spinning field is triangular, and occupies almost the entire slope 
2. Middle of the spinneret from base to point. It contains quite a number 
on areas of long spinning spools, which may be approximately estimated 
at one hundred and fifty. On each middle spinneret there are 
also three spinning spigots, of which two are close together at the tip, 
sp.c, and give issue to cylindrical glands. A little further back, another 
spigot gives exit to a treeform gland, sp.t. Along the inner base 
8. Ante- are rows of bristles. The anterior spinnerets are of stouter pro- 
Sore * portions and more conical shape than the posterior, from which 
‘and the middle spinnerets they are divided by quite an inter- 
yening space. (See Fig. 22, A, A.) Their inner bases are almost in contact 
and are divided only by a tongue like chitinous leaf, Fig. 21, t. 
Spinning 
Field. 
- 1See Bucholz and Landois. Meckel describes them as with two joints. 
