NITROGEN catabolism in animals has been assessed partly by analysis of the excretory products and partly by the identification of the enzymes in the liver or hepatopancreas. Since Strohl reviewed the excretory mechanism in the Mollusca, work on a few European marine, freshwater and terrestrial gastropods has been extended1–4. Since no data are available for an amphibious snail and no parallel record for an Indian form, so far as we know, a study was undertaken on the common Indian apple-snail Pila globosa (Swainson). This particular form, besides being amphibious, develops through a cleidoic egg. The most active period of this snail's life is during the rainy season, when it lives in fresh water and feeds and also breeds on the banks. With the approach of the winter it becomes less active and burrows in the mud to aestivate for the rest of the year until the onset of the next rainy season.