Nematode Parasitic. 101 



forming a complete riny instead of l)eing contlned to two rows. 

 It encloses in a thick layer a granular structure containing 

 branched cells closely resembling nerve cells. At about the 

 middle of its length cells begin to appear in the centre of 

 this structure, which seem to be continuous with those of 

 the alimentary canal. 



It will be seen from the foregoing description that in many 

 features this parasite resembles a nemiatode ; the entire absence 

 of reproductive structures, however, makes it impossible to 

 attempt a classification. Dr. Sweet has suggested that it may 

 be a larval form, in which case it may be a stage in the life 

 history of some already recognised species. 



EXPLANATION OF PLATES XX., XXI. 



Figs. 1 and 2. — Whole specimens of two kinds of parasite. 



,, 3. —Low power drawing of the general position of the para- 

 site in the body wall of the host. 

 ,, 4. — High power drawing of a transverse section of the 



parasite. 

 ,, 5. — (}) Nervous structure at one end of the parasite. High 



power. 

 Figs. 1, 2 and 3 outlined with camera lucida and Leitz 3 

 objective, 2 eyepiece. 



REFERENCE LETTERS. 



al. c. — Alimentary canal. 



b. V. — Blood vessel. 



c. — Capsule. 



c m. — Circular muscle, 

 e. —Epidermis of host. 

 g. c. — Goblet cell. 

 1. m. — Longitudinal muscle, 

 p. — Peritoneal membrane, 

 pig. — ^Pigment inside capsule, 

 m. — Muscle cell of parasite, 

 mes. — -Mesentery of parasite, 

 n. — Parasite. 



