SEA MUSSEL MYTILUS EDULIS. 



221 



208 



209 



210 



211 



Fig. 208.— A sporozoan parasite. Haplosporidium mytilovum, new species, in its vegetative stage, shown penetrating the wall 

 of a mussel egg. 



Fig. 209.— Haplosporidium mytilovum encysted in the cytoplasm of a mussel egg where it is undergoing a period of growth. 



Fig. 210. — A later stage than fig. 209. showing multiplication of nuclei within the cyst. The cyst is in the cytoplasm just 

 below the egg nucleus. 



Fig. 211. — A group of spores of Haplosporidium mytilovum encysted within the nucleus of a mussel egg. 



All figures are fixed in Gilson fluid and stained with Heidenhain: iron hematoxylin. X 15°°. 



90392°— 22— 7 



