Stehli, Francis G. and John W. Wells (Dept. of Geology, Case Western Reserve Univ., Cleveland, Ohio 44106 and Dept. of Geol. Sciences, Cornell Univ., Ithaca, N.Y. 14850) 1971. Diversity and patterns in hermatypic corals. Syst. Zool., 20:115–126.—Diversity and average generic age distributions for hermatypic corals show that while the Atlantic and Indo-Pacific faunas have evolved at different rates and in some respects have long been isolated systems, many responses to environment are the same. In each ocean, the diversity is highest north of the equator and in the western portion of the ocean. Positive anomalies in mean annual sea surface temperature are closely associated with maximum diversity and with minimum average generic age and a general relationship between both parameters and the area suitable for hermatypic coral growth is also evident. The data suggest that evolution of new genera is proceeding most rapidly in the regions of warmest water, but it is not possible to separate from the temperature relationship the affect of area of favorable bottom which cannot yet be quantified.