l6 OSBORN. [Vol. XVIII. 



noticed that in the cuticle there are elongate, slender, projecting 

 pieces which, in life, look much like intestinal cells, but smaller, 

 and which like them sway backward and forward with the contrac- 

 tractions of the animal. Sections show that these are parts of the 

 cuticle. I have not found traces of nuclei in any part of the 

 cuticle of the oesophagus. 



There are numerous unicellular glands in the parenchyma sur- 

 rounding the oesophagus, which differ from the parenchyma 

 glands in being smaller, and in staining well. I have not succeeded 

 in tracing ducts from these cells, and do not know whether they 

 discharge into the oesophagus or farther forward into or in front 

 of the oesophagus. Voeltzkow '88 and Stafford '96 describe 

 similar structures as salivary glands. In Aspidogaster, however, 

 the cells lie on the sides of the pharynx and discharge in front of 

 it. Glands of this sort are common in the trematodes and ter- 

 minate variously. In Polystomum (Zeller '^2) they are post- 

 pharyngal in position, and, according to Braun, discharge into the 

 pharynx posteriorly. Walter '83 describes two species of Mono- 

 stomuin. In M. proteus they are in a diffused mass surrounding 

 the pharynx and intestine, while in M. reticnlare there is a single 

 compact mass on each side which discharges into the hinder part 

 of the pharynx. In Distoinuin palHatinn (Looss '85) these glands 

 lie in a position exactly the same as in Cotylaspis. 



The intestine, as in the rest of the family, is entirely simple; 

 it is neither forked nor branched. Its wall continues the lines 

 of the oesophagus unbroken. It lies in the center of the animal 

 and extends posteriorly to a point a little in advance of the pos- 

 terior end of the body. Its wall consists of two distinct layers, 

 an inner epithelium and an outer muscular coat. The epithelium 

 is composed of cells that are attached at the base only, and are 

 entirely free from each other. They are very tall and slender, 

 some measuring 105 fi in length and 10// across the base. Others 

 are shorter and broader and have an appearance of contraction, per- 

 haps owing to the action of reagents. They are frequently 

 swollen at the free end, as in Fig. 16, and are always blunt and 

 never acute at the tip, as indicated by Alonticelli '92, Fig. 15, for 

 Cotylogasfcr imchelis. They are essentially alike in all parts of 

 the intestine, and not sharply pointed at the anterior end and 



