LIGHT AND ELECTRON-MICROSCOPY STUDY OF THE SALIVARY-GLAND SECRETORY-CELLS OF HELICOIDEA (GASTROPODA, STYLOMMATOPHORA)

We have studied the secretory goblet-cells of the salivary gland of si x species of Helicoidea: Elona quimperiana, Trissexodon constrictus, H ygromia limbata, Cernuella aginnica, Cepaea nemoralis and Helix aspers a, using light microscopy and transmission electron microscopy, In eac h of the species studied, we have been able to demonstrate the presenc e of four cell types. Following a comparative study with the goblet-gl and cells present in the six species in question, and the comparison o f our data with previously published reports on the entire set of Styl ommatophora, we have established the homologies corresponding to the c ell types observed, Our hypotheses were based primarily on the morphol ogy of the rough endoplasmic reticulum and of the secretory vesicles. Accordingly, we have defined five cell types for these six species. Th e first three cell types, A, B and C, appear in the six species studie d and seem to be present in all the stylommatophores, In order to stan dardize the terminology used by the different authors, we propose that these cell types be called: 'swollen RER cisterns mucocyte', 'granula r mucocyte' and 'alveolar cell', respectively, The D-cell type or 'bas ophilous cell' is present only in Hygromia limbata, Cernuella aginnica , Cepaea nemoralis and Helix aspersa. The E-cell type or 'vacuolated c ell' appears only in Elona quimperiana and Trissexodon constrictus.