SEA-FISHERIES LABORATORY. 187 



It is obvious from the above description that we have 

 to deal here with a Protozoon parasite, most probably a 

 Sporozoon form. Possibly it is one of the Gregarinida, 

 but at present I am unable to determine the genus. 



Explanation of Plate D. 



Fig. 1. — A small portion of the gut of the second 

 specimen. Natural size. 



Fig. 2. — Part of a transverse section of the wall of 

 the gut of the first specimen. 

 x 15 diameters. / internal, E external, 

 surface. 



Fig. 3. — Part of the same transverse section ; x 350 

 diameters. Per. peritoneum ; Ml, longi- 

 tudinal muscle layer ; Me, circular muscle 

 layer ; S.muc, sub-mucosa ; Cc, capsule of 

 a cyst ; Sp, spore contents of the cyst. 



Fig. 4. — Several spores from the first specimen 

 x 2,500 diameters. 



