Pomona College, Claremont, California 75 
found possible to remove the complete nervous system intact after 
a few trials. Ail figures are from such removed nervous systems. 
As the animals are small, being only a few millimeters in length, 
no branches but the chief ones could be preserved or shown in the 
figures. The nervous system resembles that of Thclyphorus as de- 
scribed by Borner, but as the animals are less complicated it is sim- 
pler. As in Borner's description there is brain or suprssophageal 
ganglion, a mass below the esophagus which supplies all of the 
thf)racic region and a single abdominal ganglion. The brain or su- 
perior ganglion has but one branch on each side leading from it, 
this pair leads into the jaw-like first appendages. The other five 
pairs of branches lead off from the ventral ganglion. The first two 
pairs of branches come off practically at the junction of the dorsal 
and ventral ganglia. The connection between the dorsal and ven- 
tral parts of the head-thoracic ganglia is very broad. The cells are 
small and of a uniform size for the most part. They are grouped 
in areas as shown in methylene blue preparations from which Figs. 
3 and 4 are taken. The general position of the cells is much like 
that in other arachnids. The central fibrous mass is quite homo- 
geneous in the ventral ganglionic portion, but is broken into a 
number of partly isolated portions especially at the margins. At the 
very caudal end laterally there is a very characteristic lobe of fibers 
on each side. This lobe may represent the posterior globus of 
Haller although there are no smaller cells near. Other irregular 
masses are shown in the figures. They resemble parts of the stalks 
of mushroom bodies. In the cephalic dorso-lateral regions there are 
two conspicuous groups of cells located below the main mass of 
cells and separated somewhat from each other, prominent fibers 
connect these areas with lower levels. These may represent the 
anterior globuli described by Haller, 1912, but these are of larger 
instead of composed of smaller cells. I have found nothing like 
them in arachnids. They may be something like the mushroom 
bodies of insects. 
