8 SPECIES OF CALOPLACA IN COASTAL WESTERN NORTH-AMERICA

Twenty species of Caloplaca occur on seashore rock in North America. T welve of these have been studied taxonomically in previous papers, and the remaining eight are included in this study. Four of the eight spe cies are new to science: C. ignea, C. impolita, C. inconspecta, and C. ludificans. All four species seems to be endemic to western North Ame rica. Caloplaca ignea and C. impolita are members of section Gasparrin ia, while C. inconspecta and C. ludificans belong to section Caloplaca . The other four species-C. alcarum Poelt, C. brattiae W. A. Weber, C. coralloides (Tuck.) Huh., and C. litoricola Brodo-have been poorly kn own in some respects. Knowledge about C. alcarum in continental North America is still very poor since only very scanty material is availabl e.