1. A lipid that contains glucosamine but not phosphorus has been isolated from Bacillus megaterium. It constitutes about 5% of the total lipid glucosaminide in this organism and can be distinguished chromatographically from 2'-(O-beta-glucosaminyl)phosphatidylglycerol and 3'-(O-beta-glucosaminyl)phosphatidylglycerol, which are also present. 2. The lipid contains glycerol, fatty acids and glucosamine in the molar proportion 1:2:1. The fatty acids are bound by an ester linkage and are similar to those found in other lipids of this organism. Partial acid hydrolysis or alkaline hydrolysis of the lipid yields 1-(O-beta-glucosaminyl)glycerol and degradation with nitrite yields 2,5-anhydromannose and diglyceride. 3. The lipid has been identified as 1-(O-beta-glucosaminyl)-2,3-diglyceride.