A membrane phospholipid that does not contain glycerol is

Sphingomyelins are the only sphingolipid that contains phosphate and have no sugar moiety. They are found in large quantities in nervous system. Different sphingomyelins may be formed depending on the fatty acid attached. Common fatty acids found are--lignoceric (24 C), nervonic (24 C, one double bond) and cervonic (22 C, 6 double bonds) acids (Table 7.2). Because of its amphipathic nature sphingomyelin can act as an emulsifying agent and detergent. The relative propoion of lecithin and sphingomyelin is impoant in biological fluids like bile, amniotic fluid, etc. Sphingomyelin combined with fatty acid is called ceramide, which is a component of glycosphingolipids.Ref: DM Vasudevan - Textbook of Biochemistry, 6th edition, page no: 81