IOWA ACADEMY OP SCIENCES. 
177 
side of the body, communicates anteriorly with 2, which, near 
the plane of the section turns to form 3, and so on. It is of 
interest to note that in the young animals no such coil exists. 
As the alimentary canal lengthens the loops are formed and 
gradually lengthen. Fig. 1 is reconstructed from a smaller 
and apparently younger individual than the one represented in 
section by Fig. 4, and it will be observed that the loop 4 5, 
Fig. 4, must be longer than the corresponding loop of Fig. 1, 
else the arms could not be separate at a point where the loop 
2 3, is turning. From the point 6, the intestine follows back 
along the convex border of the stomach, then rather abruptly 
turns nearly at right angles to its former course, passes through 
the ventricle of the heart, then passes over the posterior 
adductor muscle dorsally and posteriorly to open in the cloacal 
chamber. The typhlosole is not strongly developed but is 
present as a small ridge as shown in Fig. 5. 
The alimentary canal throughout its length is lined by 
elongated ciliated epithelial cells. Fig. 9 represents these 
cells as they appear in a section through the lower end of the 
stomach. 
LIVER. 
The liver, Fig. 1, I, is a paired organ, consisting of two 
large racemose glands, one on each side of the body. Each 
gland communicates with the stomach through anterior lateral 
pouches. The liver cells are often densely crowded with gran- 
ules that stain deeply, but not infrequently part of the cells of 
some follicles will be full while adjacent cells will be empty. 
This condition is indicated by Fig. 10. 
It is not unlikely that, as the animal probably feeds most of 
the time, digestion is a continuous process and that the liver 
cells are continually filling up and discharging. 
NERVOUS SYSTEM. 
The regular three pairs of LamelL branch ganglia are pres- 
ent. The cerebral ganglia. Fig. 1, c. g. lie on opposite sides of 
the oesophagus, on a level with the dorsal end of the anterior 
adductor muscle. They are somewhat oblong in shape and are 
connected with each other by an oesophageal commissure which 
runs between the oesophagus and the anterior adductor muscle. 
The parieto- splanchnic ganglia Fig. 1, p s g, also oblong in 
shape, lie anterior to the ventral portion of the posterior 
adducbcr muscle and are fused together by their adjacent sides. 
The pedal ganglia, Fig. 1, p g, are more nearly circular than 
12 
