3 o8 



OS BORN. 



[VOL. I. 



Two very distinct suckers are present ; the anterior one 

 surrounding the mouth is considerably smaller than the ventral, 

 and located at the extreme anterior end of the body. The 

 ventral sucker is very large and prominent. It is on the level 



mfc.Ex.Vsc 



FIG. 4. 



FIG. 3. 



FIG. 3. Drawing of the distomid, from life. 



FIG. 4. Drawing of the distomid, from a total preparation in balsam after corrosive subli- 

 mate and borax-carmine. 



of the surrounding surface, is slightly wider than half the 

 diameter of the body at its level, and is located very slightly 

 behind the center of the ventral surface. 



The body wall is as usual ; its musculature can be seen in 

 sections, greatly increased in amount at the suckers, and bound' 

 ing the customary parenchymatous filling of the body cavity. 



The alimentary organs are considerably differentiated. The 

 pharynx closely follows the mouth ; its wall is much thickened, 

 and internally it is distinctly lined with nucleated columnar 

 cells. The alimentary passage divides immediately behind the 

 'pharynx, without any intermediate oesophagus, into two intes- 

 tinal tubes. These are entirely simple, and present an anterior 

 portion lined with taller glandular cells shading posteriorly into 

 a part, bounded by a flat-celled epithelium. So that in total 

 mounts the anterior portion is dark and the hinder portion is 

 clear and bladdery. 



