Complex sentence: The "Santa Monica" name for the springs came later Handcock, Ralph, "Fabulous Boulevard", Funk & Wagnalls, 1949 and was commonly called that by the turn of the 19th century.
Split into simpler sentences: The "Santa Monica" name for the springs came later Handcock, Ralph, "Fabulous Boulevard", Funk & Wagnalls, 1949. The springs were probably commonly called by the name "Santa Monica" by the turn of the 19th century.