Richard Harris, of Michigan State University, introduced me to the C. ciliaris complex, and especially to certain questions surrounding the distribution of the acids in the lichen in the region of UMBS near Pellston, Michigan, near the Straits of Mackinac. In that summer of 1967 I became curious about ecological factors which might affect the distribution of C. ciliaris. ... The species of the C. ciliaris complex are (seemingly) randomly scattered in all communities which occur within areas in which the species are sympatric. No differing ecological requirements have been shown to be attributable to one species or the other in this or other works. This type of investigation must be undertaken in areas in which the three species occur sympatrically, such as the region of the central Appalachians investigated by Hale in 1963. However, in his work there, C. orbata was represented by only 0.3% of the thalli collected (cf. 0.4% in my study near the Straits region of Michigan) and would prevent any ecological or microenvironmental study of its distribution.