Some microalga species may accumulate extracellular polysaccharides, such as a gelatinous mass that encloses its cells, and is known as envelopes, sheaths or capsules. These structures are very common among the Desmidiales. However, studies concerning their functions, properties and structures are still incipient. Spondylosium panduriforme is a filamentous desmids, enclosed by a great and continuous capsule with well-defined borders firmly bond to the cell. These characteristics can be observed through light microscopy in Indian ink preparations. The S. panduriforme capsule is taken as an essential part of the cell, and points out the importance of this structure for its proper functioning [1,2].