538 GENERAL ANATOMY. 



the neck almost wanting, the anterior articulations in the form 

 of wrinkles, those which follow are broad and short, the last 

 elongated; its length is twenty feet or more. This species is 

 common in Switzerland and Russia, very rare in England, 

 Holland, and Germany. It is not found in dead bodies. 



The solitary or armed tsenia, T. solium, called also com- 

 monly, and improperly^ solitary worm, has the head furnish- 

 ed with four suckers, and an obtuse proboscis,* armed with 

 hooks in their centre; the head is hemispherical, and distinct; 

 the neck thickens anteriorly; the anterior articulations are 

 very short, the following elongated, the last longer, all obtuse, 

 provided each with a marginal pore, alternating indefinitely 

 sideways; its length is from five to ten feet and more. This 

 species is common in England, Holland, and Germany. It 

 is sometimes met with in dead bodies. 



Both species are found in France, but particularly the se- 

 cond. They both inhabit the intestinal canal, especially the 

 small intestines. 



854. The distoma, or the fasciola^ (Lin.) has the body 

 soft, depressed, and two solitary pores, one anterior and one 

 ventral. 



The hepatic distoma, D. hepaticum, which has the form of 

 an oval leaf, is met with in the gall bladder of man and of 

 many other animals, particularly of the sheep. 



The polystoma, hexathyridium, (Treuther,) has the body 

 depressed, six anterior pores, one ventral, and one posterior. 

 The P. of the fat, P. pinguicola, which is truncated before, 

 pointed behind, has been met with in a tumour of the human 

 ovary. The polystoma of the veins, P. venarum, appears 

 to be an external worm. (457) 



III. OP CYLINDRICAL WORMS. 



855. The cylindrical worms, Ent. nematoidea, (Rud.), 

 have the body elongated, rounded, and elastic; they have an 

 intestinal canal, terminated by a mouth and anus, genital or- 

 gans, separate on two different individuals. This order com- 



