Definition: Cryptonemertes is a term used in the field of biology that describes a type of bacterium commonly found in soil and water, known as "cryptomonas." These bacteria are characterized by their ability to form cryptic structures on surfaces or in the air, which can then be observed under the microscope. Cryptomonas is an essential part of the food chain for many organisms, as they help break down plant matter into simpler compounds that can be used by other organisms.