GROUP OF UNCERTAIN POSITION 



3447 



around which is arranged a series of whiter cells, partly projecting like papillae from 

 the surface. At the front end the cells of the external layer form a symmetrical 

 head, by which the parasite attaches itself; but there are no distinct nervous, diges- 

 tive, or muscular organs. 



A DICYEMID. 



(Enlarged twenty times.) 



