204 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
very distinctly rounded off, forming an uneven lower 
margin, which rests on a fibrous sheath consisting of 
several layers, and which passes into the loose connective 
tissue surrounding the digestive gland tubules. 
The thickness and extent of the tricuspid body is 
variable, some portions of the stomach-wall being bare; 
the latter is thrown into folds and pads, into which the 
substance of the tricuspid body dips. In most parts this 
substance is closely adherent to the gastric epithelium, in 
other parts it is distinctly separated; where it lies in 
close contact with the epithelium the striated free border 
of the latter is very evident. Where it is separated the 
epithelium is seen to bear cilia which, at other places, 
must be embedded in its substance. It stains slightly 
with eosin. No obvious structure can be discerned in it 
except that in favourable preparations, delicate strie, 
parallel to the surface of the epithelium, and other striz 
perpendicular to the surface may be seen, which seem to 
indicate that it has been deposited round the cilia and in 
lamine, perpendicular to the surface of the epithelium. 
Where the tricuspid body is wanting the gastric epithelium 
is composed of much shorter spindle cells than are found 
elsewhere. The average length of the cells beneath the 
tricuspid body is 0°08 mm., on the rest of the stomach- 
wall 0°04 mm. ; 
The whole posterior part of the stomach contracts to 
form the straight portion of the intestine (Al.c.3, fig. 3). 
This extends downwards nearly in the axial line of the 
proximal hmb of the viscero-pedal mass. It is shghtly 
curved, the concavity being anterior. The diameter, the 
average value is 1°25 mm., decreases from above down- 
wards. At the lower end and on the anterior side, the 
spiral portion of the intestine takes origin, below this there 
is a short anteriorly directed caecum. 
