Morphology and morphogenesis of a Spanish population of Urosomoida agiliformis (Ciliophora, Hypotrichida) from a wastewater treatment plant

The morphology and morphogenesis of a population of the hypotrichous ciliat e Urosomoida agiliformis from a wastewater treatment plant with a RBC syste m are described. This population is compared with some populations of U. ag iliformis studied previously. The Spanish population shows an infraciliary pattern similar to Austrian and Israeli populations of Oxytricha longa stud ied before. However, the morphogenesis in this case is similar to some soil populations of U. agiliformis from alpine pastures in Austria. The morphol ogy and division morphogenesis for this Spanish population are schematised in a computer drawing using symbols. An improved diagnosis for the genus Ur osomoida is also provided.