No. 416.] THE TEXAN KG NENIA. 625 
abdominal ganglion, which has not been drawn up toward the 
head in the latter, but remains in the eighth segment. 
Digestive System. — The downward-curved, crescentic mouth 
leads into a strongly chitin-lined pharynx. This in turn runs 
into a very delicate cesophagus which penetrates the cepha- 
lothoracic nerve mass, only to dilate immediately into a 
pouch-like sucking stomach. This stomach is roofed over 
by the brain, while underneath it the subcesophageal ganglion 
extends. At the sides the brain is not continuous with the 
suboesophageal ganglion, thus leaving a passageway for mus- 
cles arising from the sides of the cephalothorax to enter and 
attach themselves to the stomach. When expanded to its 
utmost the stomach fits snugly in between the two ganglia, but 
when pulled on by the muscles it is flattened dorso-ventrally. 
The comparatively thick-walled stomach opens through a valve- 
like constriction into the exceedingly thin-walled intestine. 
The intestine, before it leaves the thorax, gives off a pair of 
small diverticula. It then passes into the abdomen, becoming 
much dilated, and giving off five shallow metameric pairs of 
diverticula, from the third to the seventh segments inclusive. 
These diverticula are very diagrammatically represented in 
Figs. 5 and 6, as are all the other organs, save the brain 
and the anterior portion of the digestive tract as far back as 
to the first pair of diverticula. At about the eighth segment 
the thick-walled large intestine begins. Unlike Thelyphonus, 
no Malpighian tubules are present, opening into the hind gut, 
before it terminates at the anus. On this point Kcenenia is 
most primitive, since it seems not yet to have reached the 
stage in which intestinal diverticula become modified as excre- 
tory organs. There are also no salivary glands present ; these 
would hardly be of any use to an animal living under such 
simple conditions. The intestine and diverticula are invari- 
ably filled with food particles, which have the appearance of 
yolk granules. Strange to say, — because of the conditions 
under which Koenenia is found, — throughout the entire digest- 
ive tract no dirt ever appears. This goes to prove that the 
food is probably derived, as Dr. Wheeler has already suggested, 
from the eggs of animals with which it associates. The 
