The persistence in the literature of the older and often incorrect generic names formerly bestowed on many of the cocci encountered in the brewing process (e.g., “Sarcina,” “Pediococcus,” “Micrococcus,” “Tetracoccus,” etc.) obscures the fact that they are almost always true lactic acid bacteria belonging to the family Lactobacteriaceae, and not to the family Coccaceae. In an accompanying table such bacteria are re-classified in the appropriate genus Streptococcus, the opportunity being additionally taken to include rod forms In the genus Lactobacillus, so as to illustrate the phylogenetic inter-relationship of the two types and to furnish a guide by means of which existing species may be initially differentiated on a broad basis.