"Great spangled fritillaries!" exclaimed Grandpa. "They've gone and done it at last." Or so we imagine one reaction to the first organized butterfly census of Manhattan and the Bronx. Not only fritillaries but silvery checkersports, red admirals, and a common sooty-wing were seen among 27 varieties in a population of 401. A serious purpose: monitoring possibly endangered species. But no netting, just finding and counting and watching summer's creatures go -- who wouldn' t like to join that kind of a hunting party?