Colpoda spiralis sp. n., a Colpodid Ciliate Found Inhabiting Treeholes (Colpodida,Ciliophora)*

SYNOPSIS A new species of the family Colpodidae, genus Colpoda O. F. Müller, Colpoda spiralis sp. n. is described. This organism has been found only in treehole fluid. Its species status is based on the possession of a unique and prominent preoral protuberance, multimicronuclearity, and the preference for a treehole habitat. Its range is known to include the tri-state area of Arizona, New Mexico and Utah, and the mixed-deciduous forests of Maryland. This species prefers treehole fluids with a pH > 7 and is naturally limited to tree species which possess these alkaline treeholes. It encysts as a treehole dries and excysts when the treehole is again filled by fluids from the tree, or rainwater.