Pomona College, Claremont, California 75 



found possible to remove the complete nervous system intact after 

 a few trials. All 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 Thelyphorus 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 suprsesophageal 

 ganglion, a mass below the esophagus which supplies all of the 

 thoracic region and a single abdominal ganglion. The brain or su- 

 perior ganglion has but one branch on each side leading from it, 

 this pair leacis into the jaw-like first appenciages. The other five 

 pairs of branches lead off from the ventral ganglion. The first two 

 pairs of branches come off practicallv 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. Thev are grouped 

 in areas as shown in methvlene 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 ganQ:lionic 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 mav 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. Tn 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 le\^els. These mav represent the 

 anterior globuli described by Haller, 1912, but these are of larger 

 instead of composed of smaller cells. T have found nothing like 

 them in arachnids. Thev may be something like the mushroom 

 bodies of insects. 



