The voluminous amounts of biological information collected for the Mississippi Estuarine Inventory required the development of a system for the automatrc processing of this data. The prime requirement of such a system was preparing a taxonomic code that could be easily updated and efficiently handled by EDP equipment. A modified version of the phylogenetic taxonomic structure was used to reduce the extent of the code and make optimum use of computer time. By the use of several search algorithms, computer memory requirements were substantially reduced. The utilization of the coded input to present an output with scientific names rather than code eliminated the undesirable need for double reference. The necessity for the biologist to be involved directly with the processing is eliminated, thus freeing him to devote his talents to the comprehensive interpretation of the results.