Preliminary studies revealed massive deposits of highly metachromatic substances adherent to the cuticula of the cercaria of Paragoniwzus kellicotti Ward, '08. The role of mucoid materials in the economies of other groups of cercariae (Kruidenier, '51, 53a, '53b) led to further consideration of the formation and function of mucoids in this microcerous species.
Varying descriptions of a group of prominent, "glandlike" cells in the cercaria of Paragomirnus have been presented. Kobayashi ('21) figured 8 or 9 pairs of median ventral cells. Ameel ('34) found such cells in specimens from all of his laboratory infected snails but from only 9% of the naturally infected snails collected. He distinguished large, ventral cells with fine cytoplasm and a high affinity for neutral red from small, lateral and ventral cells with coarse cytoplasm and lessened affinity for that dye. The large cells were most frequently confined to the post-acetabular region (2-6 pairs). I n the cercariae from one snail, however, "as many as 12-14'' of the large cells extended almost the entire length of the body. Five of the small cells occurred along each margin and three pairs ' ' occasionally7 were dis-Sincere gratitude f o r his valued suggestions is expressed to Dr.