Kier, Porter M Triassic echinoids / Porter M. Kier - Washington Smithsonian Institution Press 1977 - iv, 88 p. : ill. ; 26 cm. - Smithsonian contributions to paleobiology ; no.30. . Includes index. Bibliography: p. 39-41. LCCN: 76-024806 //r892 Subjects--Topical Terms: Sea urchins, FossilPaleontology--Triassic