Colonial coral 5. Lace-like fossils; occur as thin sheets or films Bryozoa 6. Fossils composed of radiating masses of polygonal or circular tubes containing radial septa Colonial coral 7. Irregular fossils; typically cylindrical with rough surface: a. Fossil has large axial opening and thick wall; usually has external longitudinal ribs. Occurs only in Cretaceous rocks Rudistid b. Fossil solid with no large axial opening; surface with small pits or pores (fewer than in Bryozoa). In Texas, occurs most commonly in Pennsylvanian and Permian rocks Sponge LIST OF TEXAS COLLEGES OFFERING GEOLOGY COURSES A.&M. College of Texas, College Station Amarillo College, Amarillo Arlington State College, Arlington Austin College, Sherman Baylor University, Waco Blinn College, Brenham Corpus Christi, University of, Corpus Christi Del Mar College, Corpus Christi East Texas State College, Commerce Hardin-Simmons University, Abilene Henderson County Junior College, Athens Houston, University of, Houston Howard County Junior College, Big Spring Kilgore College, Kilgore Lamar State College of Technology, Beaumont Lee College, Baytown McMurry College, Abilene Midwestern University, Wichita Falls North Texas State College, Denton Odessa College, Odessa Pan American College, Edinburg Rice University, Houston St. Mary’s University, San Antonio San Angelo College, San Angelo San Antonio College, San Antonio Southern Methodist University, Dallas South Texas College, Houston Southwestern University, Georgetown Stephen F. Austin State College, Nacogdoches Sul Ross State College, Alpine Tarleton State College, Stephenville Texarkana College, Texarkana Texas Christian University, Fort Worth Texas College, Tyler Texas College of Arts and Industries, Kingsville Texas Technological College, Lubbock Texas Western College, El Paso The University of Texas, Austin Trinity University, San Antonio Tyler Junior College, Tyler West Texas State College, Canyon [Illustration: Plate 6 Fossil Identification Chart I RADIAL SYMMETRY]