PETERSON FIRST GUIDES: REPTILES AND AMPHIBIANS <i> by Roger Conant, Robert C. Stebbins & Joseph T. Collins </i> and SEASHORES <i> by John C. Kircher (Houghton-Mifflin: $4.95 each, illustrated).</i>

These two simplified guides offer a readily approachable introduction to nature study for students--and/or parents who want to know just what slimy thing Junior’s brought home this time. “Reptiles and Amphibians” explains how to observe and photograph animals in their natural habitats without disturbing them. The section on snakes includes a simple formula that will enable anyone to distinguish the extremely venomous coral snakes from similar-looking harmless species. (If the red and yellow bands touch, the snake is poisonous: “Think of a traffic light: yellow means caution, red means stop.”) The illustrations show the reader exactly where to look on the animals for identifying features. “Seashores” is also handsome and informative, but Kircher devotes too much of the text to Atlantic environments: The entire Pacific coast receives only 11 pages at back of book.