Five picture books worth a look; Adeline Schlime, by Tatjana Hauptmann. New York: Holt, Rinehart & Winston. $10 .95.

Adeline Schlime is a snail. She has been chosen to sing the lead role in the well-known snail operetta "Slow But Easy." Quite understandably, she is nervous as she prepares for opening night. Since snails are slow, it takes a very long time. Her preparations are hampered by son Oscar, the slowest snail in town, who doesn't want to go anyway. Fortunately, Oscar finds a car parked nearby; they hitch a ride on its hubcap, arriving with time to spare, and the evening is a huge success.

The author's colorfully detailed drawings give an amusing snail's eye view of the world. The book was originally published in German with the title "Adelheid Schle im."