effective, average, marginal. -The effective tax rate is the best measure of the tax burden because it is the average level of tax on all income from taxable and nontaxable sources. -The average tax rate measures the average level of tax on only taxable income.
Navigating the eschaton. The eschaton is something to be avoided and something to be courted. It is a virtual singularity of human consciousness marking the end of the historical epoch. In itself it is a neutral event, one to be reckoned with. It is a point of leverage for wielding the human spirit.
Chitons are primitive marine molluscs in the class Polyplacophora (formerly the class Amphineura). There are 900 to 1,000 living species of chitons. Their size ranges from 0.5 to 30 cm in length; most are quite small. All the living species are in the subclass Neoloricata, and so may be called 'loricates'. Popular names are sea cradles or coat-of-mail shells.