Stephanochasmus Looss 
230 
The two suckers are of rather small size, the oral sucker (Fig. 1, 27), 
which is terminal in position, having a diameter, in the specimen 
figured, of 0-29 mm. and the acetabulum (Fig. 1, l) one of 0-49 mm. 
A pair of groups of pigment granules (Fig. 1, 32) is present in the 
dorsal body wall a short distance behind the pharynx, which, as Looss 
(1901) has shown, are the remains of the cercarian eyes and charac¬ 
terize most of the species of the genus. The granules composing each 
eye are very distinct and number from 20 to about 50. In much 
contracted specimens they are often crowded closely together or form 
a single mass, while in extended worms they are more or less separated 
from one another. 
The mouth is cup-shaped, having a characteristic semi-circular 
outline, and opens into a long prepharynx (Fig. 1, 33) which in the 
specimen figured is 0-65 mm. long. The hinder end forms a circular 
fold around the anterior end of the pharynx (17), which is a large 
piriform organ (31) 0-33 mm. long and 0-22 mm. thick. 
An oesophagus (25) is present which is very short and wide, measuring 
0-06 mm. in length and 0-2 mm. in width. It is really a part of the 
intestine inasmuch as it possesses its characteristic epithelium. The 
prepharynx, on the other hand, has the structure which usually charac¬ 
terizes the oesophagus of trematodes, as it possesses no epithelium and 
its lumen is bounded by a cuticula. It functions, in fact, as an oeso¬ 
phagus which has the pharynx at its hinder end instead of at its forward 
end. 
The two intestinal trunks (20) pass at once transversely to the lateral 
areas of the body and then to the hinder end of it and are very wide, 
measuring 0-13 mm. in diameter. Their epithelium consists of cells 
which vary much in height and shape in different individuals. In one 
of the four worms sectioned they were simple cubical or somewhat 
elongated cells throughout the greater part of the intestine which did 
not possess terminal filaments. In the other worms examined the 
shape of the epithelial cells of the intestine had apparently been 
influenced by the food contents of the gut, and in a very interesting 
way. In the worm of which Figure 3 represents a cross section- and 
Figure 4 a portion of the intestinal epithelium, the cells of this epi¬ 
thelium are, throughout a large part of the gut, considerably elongated, 
and with large nuclei, and from their free surfaces a fringe of long 
filiform protoplasmic processes extends into the lumen of the intestine. 
These processes are considerably longer than the cells themselves and 
four or five of them appear in a section extending from each cell (Fig. 4). 
