MONOGRAPH OF THE GENUS STROPHIA. 
back of this mouth, protrudes a cylindrical, upturned organ, ib., 7, 9, 
k 11, T, at the outward extremity of which, is attached a thin muscle, 
Plate I, 7, 9, & 11, c, that passing backward and downward obliquely, 
terminates on a broad, though thin, muscle, ib., 7, 9, & 11, oc. With- 
in we find that the cylindrical projection terminates at the base of 
a double tongue-like muscle, the termination of which is free and projects 
well into the chamber, ib., 9, ct, where a side view is given, and ib., 8, 
ct, where a front view of this remarkable organ is represented. The 
edges of this tongue are turned upward, and in the contracted animal, 
the upper surface is turned backward, so that the tip rests against the 
upper wall of the mouth. Both the terminal portion of the tongue, on 
each surface, and the inside of the cylinder, are covered with a membrane 
that supports regular rows of numerous teeth which point backward, as 
given in ib., 9, d; tt, being the cylinder detached. As is evident, from 
the retractor muscle, ib., 7, 9, & 11, c, this whole arrangement is capable 
of being protruded forward so that the tip of the tongue will perhaps be 
brought in contact with the cutting edge of the jaw. The animals that 
I have examined, although living, had been fasting for over six months 
and thus not a vestage of food remained in the stomach, so it is difficult 
to judge whether the cylinder performed any of the labor of digestion; 
but in several instances, if not in all examined, this organ was filled with 
a kind of thick gelatinous substance: ib. 8, T, shows the entrance of the 
cylinder. 
The oesophagus, see ib. 7, 8, 9, & 11, 1, emerges from the top of the 
stomach, a little to the left, and turning downward and backward, passes 
between and below two sets of glands, ib., 7 & 11, p, the posterior por- 
tions of which are fastened by tissues to the muscle, ib., 7, 9, &ll,oc. 
These glands which have a granular appearance, evidently pour a sol- 
vent fluid into the mouth, or as I am inclined to regard it, the proven- 
triculus, through the duct shown at ib., 7, H, The stomach is long and 
narrow, not being much larger than the intestine, and ends at the lower I, 
ib., 7. Beyond this point the intestine begins and enters the substance of 
the liver, which is of a greenish color and which occupies the terminal 
five whirls of the abdomen; the alimentary canal is now supplied with 
absorbents that terminate in a common duct which is apparent outside 
the liver, on the inner of spiral side. The intestine proceeds downward 
as far as the beginning of the fifth whirl of the body at a point about 
oppositeib.,5 , am. It then turns upward, emerging from the liver on 
the left side of the second whirl, ib., 5, it, passes around to the right of 
the back, where it becomes the rectum, ib., 6, R. and emerges at the 
vent, ib., G, v. 
